ABSTRACT

The Xbox is a video gaming brand created by Microsoft. It includes a series of video game

consoles developed by Microsoft, with consoles in the sixth to eighth generations, as well

as applications (games), streaming services, and the online service, Xbox Live. The brand

was first introduced on November 15, 2001 in the United States, with the launch of

the original Xbox console.

That original device was the first video game console offered by an American company after

the Atari Jaguar stopped sales in 1996. It reached over 24 million units sold as of May 10,

2006. Microsoft's second console, the Xbox 360, was released in 2005 and has sold over 77.2

million consoles worldwide as of April 18, 2013. The successor to the Xbox 360 and

Microsoft's most recent console, the Xbox One, was revealed on May 21, 2013. The Xbox

One has been released in 21 markets around the world on November 22, 2013, with the UK

as its first country. The head of Xbox is Phil Spencer, who succeeded former head Marc

Whitten in late March 2014.

1.Introduction

1.1 The XBOX System

The Xbox is a video gaming brand created by Microsoft. It includes a series of video game

consoles developed by Microsoft, with consoles in the sixth to eighth generations, as well

as applications (games), streaming services, and the online service, Xbox Live. The brand

was first introduced on November 15, 2001 in the United States, with the launch of

the original Xbox console.

That original device was the first video game console offered by an American company after

the Atari Jaguar stopped sales in 1996. It reached over 24 million units sold as of May 10,

2006. Microsoft's second console, the Xbox 360, was released in 2005 and has sold over 77.2

million consoles worldwide as of April 18, 2013. The successor to the Xbox 360 and

Microsoft's most recent console, the Xbox One, was revealed on May 21, 2013. The Xbox

One has been released in 21 markets around the world on November 22, 2013, with the UK

as its first country. The head of Xbox is Phil Spencer, who succeeded former head Marc

Whitten in late March 2014.

In 1998, four engineers from Microsoft's DirectX team, Kevin Bachus, Seamus Blackley, Ted

Hase and DirectX team leader Otto Berkes, disassembled some Dell laptop computers to

construct a prototype Microsoft Windows-based video game console. The team hoped to

create a console to compete with the Sony's upcoming PlayStation 2, which was luring game

developers away from the Windows platform. The team approached Ed Fries, the leader of

Microsoft's game publishing business at the time, and pitched their "DirectX Box" console

based on the DirectX graphics technology developed by Berkes' team. Fries decided to

support the team's idea of creating a Windows DirectX based console.

During development, the original Direct Xbox name was shortened to Xbox. Microsoft's

marketing department did not like the Xbox name, and suggested many alternatives. During

focus testing, the Xbox name was left on the list of possible names to demonstrate how

unpopular the Xbox name would be with consumers. However, consumer testing revealed

that Xbox was preferred by far over the other suggested names and "Xbox" became the

official name of the product.

The Xbox was the second console produced by an American company since the Apple

Pippin ceased production in 1997, after the release of the Nuon in 2000. It Microsoft's first

video game console after collaborating with Sega to port Windows CE to the

Dreamcast console. Microsoft repeatedly delayed the console, which was first mentioned

publicly in late 1999 during interviews with Microsoft's then-CEO Bill Gates. Gates stated

that a gaming/multimedia device was essential for multimedia convergence in the new times.

He has even been quoted as saying "if we do not advance, to the next generation, we will

most surely fall behind our competitors (Apple)".

The Xbox was officially announced at the Game Developers Conference on March 10,

2000. Audiences were impressed by the console's technology. At the time of Gates'

announcement, Sega's Dreamcast sales were diminishing and Sony's PlayStation 2 was just

going on sale in Japan.The Xbox was officially unveiled to the public by Gates and guest

professional wrestler The Rock atCES 2001 in Las Vegas on January 3, 2001. Microsoft

announced Xbox's release dates and prices at E3 2001 in May. Most Xbox launch titles were

unveiled at E3, most notably Halo: Combat Evolved and Dead or Alive 3]

Due to the immense popularity of gaming consoles in Japan, Microsoft delayed the release of

the Xbox in Europe to focus on the Japanese video game market. Although delayed, the

European release proved to be more successful than the launch of the Xbox in Japan.

Some of Microsoft's plans proved effective. In preparation for its launch, Microsoft

acquired Bungie and used Halo: Combat Evolved as its launch title. At the time, Golden Eye

007 for the Nintendo 64 had been one of the few hit FPS games to appear on a console, some

of other ones being Perfect Dark and Medal of Honor. Halo: Combat Evolved proved a good

application to drive the Xbox's sales. In 2002, Microsoft made the second place slot in

consoles sold in North America. The Xbox Live service gave Microsoft an early foothold in

online gaming and would help the Xbox become a relevant competitor to other sixth-

generation consoles.

Popular launch games for the console included Dead or Alive 3, Amped: Freestyle

Snowboarding, Halo: Combat Evolved, Fuzion Frenzy, Project Gotham Racing, and Jet Set

Radio Future.

Consoles

Xbox Xbox (console)

Xbox console with "Controller S"

The original Xbox was released on November 15, 2001 in North America, February 22, 2002

in Japan, and March 14, 2002 in Australia and Europe. It was Microsoft's first foray into the

gaming console market. As part of the sixth-generation of gaming, the Xbox competed

withSony's PlayStation 2, Sega's Dreamcast (which stopped American sales before the Xbox

went on sale), and Nintendo's GameCube. The Xbox was the first console offered by an

American company after the Atari Jaguar stopped sales in 1996. The name Xbox was derived

from a contraction of DirectX Box, a reference to Microsoft's graphics API, DirectX.

The integrated Xbox Live service launched in November 2002 allowed players to play games

online with a broadband connection. It first competed with Dreamcast's online service but

later primarily competed with PlayStation 2's online service. Although these two are free

while Xbox Live required a subscription, as well as broadband-only connection which was

not completely adopted yet, Xbox Live was a success due to better servers, features such as

a buddy list, and milestone titles like Halo 2 released in November 2004, which is the best-

selling Xbox video game and was by far the most popular online game for years.

Xbox 360

Left: Xbox 360 Elite, Right: Xbox 360 S and new-style controller

The Xbox 360 was released as the successor of the original Xbox in November 2005,

competing with Sony's PlayStation 3 and Nintendo's Wii as part of the seventh generation of

video game consoles. As of June 30, 2013, 78.2 million Xbox 360 consoles have been sold

worldwide. The Xbox 360 was officially unveiled on MTV on May 12, 2005, with detailed

launch and game information divulged later that month at the Electronic Entertainment

Expo (E3). The console sold out completely upon release in all regions except in Japan.

The Xbox 360 introduced an expanded Xbox Live service (which now included a limited

"Free" tier), the ability to stream multimedia content from PCs, while later updates added the

ability to purchase and stream music, television programs, and films through the Xbox

Music and Xbox Video services, along with access to third-party content services

through third-party media streaming applications. Microsoft also released Kinect, a motion

control system for the Xbox 360 which uses an advanced sensor system.

At their E3 presentation on June 14, 2010, Microsoft announced a redesigned Xbox 360 that

would ship on the same day. The redesigned console is slimmer than the previous Xbox 360

model and features integrated 802.11 b/g/n Wi-Fi, TOSLINK S/PDIF optical audio output,

five USB 2.0 ports (compared to the three from older versions) and special port designed for

the Kinect peripheral. Older models of the Xbox 360 have since been discontinued. The first

new console to be released features a 250 GB hard drive, while a later less

expensive SKU features 4 GB internal storage.

Xbox One

Main article: Xbox One

The Xbox One with the redesigned Kinect and controller

The Xbox One was released on November 22, 2013 in North America, as the successor of

the Xbox 360. The Xbox One competes with Sony's PlayStation 4 and Nintendo's Wii U as

part of the eighth generation of video game consoles.

Announced on May 21, 2013, the Xbox One will place a large emphasis on internet-based

features; including the ability to record and stream gameplay, and the ability to integrate with

a set-top box to watch cable or satellite TV through the console with an enhanced guide

interface and Kinect-based voice control.

Following its unveiling, the Xbox One proved controversial for its original digital rights

management and privacy practices; while Microsoft touted the ability for users to access their

library of games (regardless of whether they were purchased physically or digitally) on any

Xbox One console without needing their discs, and the ability to share their entire library

with 10 designated "family" members, all games would have to be tied to the user's Xbox

Live account and their Xbox One console, and the console would be required to connect to

the Internet on a periodic basis (at least once every 24 hours) in order to synchronize the

library, or else the console would be unable to play any games at all. After an

overwhelmingly negative response from critics and consumers (who also showed concerns

that the system could prevent or hinder the resale of used games), Microsoft announced that

these restrictions would be dropped.Microsoft was also criticized for requiring the Xbox One

to have its updated Kinect peripheral plugged in to function, which critics and privacy

advocates believed could be used as a surveillance device. Despite showing a commitment to

user privacy, Microsoft still ultimately decided to allow the console to function without

Kinect.

Comparison

Xbox Xbox 360 Xbox One

Console

Console

Launch

price

US$299.99

GB£299.99

€479,99

US$299.99 (Core) (discontinued)

US$399.99 (Premium – 20 GB)

(discontinued)

US$249.99 (Premium – 60 GB)

(discontinued)

US$479.99 (Elite) (120 GB)

(discontinued)

US$299.99 (Arcade – 256 MB

internal memory) (discontinued)

US$199.99 (Arcade – 512 MB

internal memory) (discontinued)

US$299.99 ("Super Elite")

(250 GB) (discontinued)

US$399.99 (Xbox 360 S – 250 GB

+ Kinect)

US$299.99 (Xbox 360 S –

250 GB)

US$299.99 (Xbox 360 S – 4 GB

internal memory + Kinect)

US$199.99 (Xbox 360 S – 4 GB

internal memory)

US$499

GB£429

€499

US$199.99 (Xbox 360 E – 4 GB

internal memory)

US$299.99 (Xbox 360 E –

250 GB)

US$299.99 (Xbox 360 E – 4 GB

internal memory + Kinect)

Release

date

NA November 15, 2001

JP February 22, 2002

EU March 14, 2002

November 22, 2005

EU December 2, 2005

JP December 10, 2005

AUS March 23, 2006

Further information: Xbox 360

launch#Release dates and pricing

November 22, 2013

Discontinue

d

JP 2007

NA 2008

EU 2008

N/A N/A

Units sold

24+ million (as of May 10,

2006)

77.2 million (as of April 18,

2013)

3 million (as of January 6,

2014)

Best-selling

game

Halo 2, 8 million (as of May 9,

2006)

Kinect Adventures (pack-

in with Kinect peripheral),24

million

Best selling non-bundled

game: Call of Duty: Modern

Warfare 3, 14.23 million

N/A

Media CD, DVD CD, DVD, HD DVD (movies

only) with add-on drive CD, DVD, Blu-ray Disc

Accessories

(retail)

Xbox Live Starter Kit

Xbox Media Center

Extender

DVD Playback Kit

Xbox Music Mixer

see Xbox 360 accessories TBA

Memory Unit (8 MB)

Logitech Wireless

Controller (2.4 GHz)

More...

CPU

733 MHz x86 Intel

Celeron/Pentium III Custom

HybridCPU

3.2 GHz IBM PowerPC tri-

core CPU codenamed "Xenon"

1.75 GHz AMD x86-

64 eight-

core CPU codenamed

"Jaguar‖

GPU

233 MHz nVidia custom GeFor

ce 3 NV2A DirectX 8.0 based

GPU

500 MHz ATi custom Radeon

X1800 DirectX 9.0c based GPU

codenamed "Xenos"

853 MHz AMD Radeon

HD 7000 series DirectX

11.1 based GPU

codenamed "Durango"

Memory

64 MB DDR SDRAM @

200 MHz; in dual-channel 128-

bit configuration giving 6400

MB/s

512 MB of GDDR3 RAM @

700 MHz 22.4 GB/s, 10

MB EDRAM GPU frame buffer

memory

8 GB of DDR3 RAM @

2133 MHz 68.3

GB/s, 32

MB ESRAM GPU

frame buffer memory

Video I/O

VGA, Component (YPbPr

), SCART, S-

Video,Composite

1080i, 720p, 576p, 576i, 4

80p, 480i

HDMI (on models

manufactured after August

2007), VGA, Component/D-

Terminal (YPbPr),SCART, S

-Video, Composite

1080p, 1080i, 720p, 576p, 57

6i, 480p, 480i

Various monitor resolutions

available via VGA and

HDMI/DVI (640×480, 848×480,

1024×768, 1280×720, 1280×768,

1280×1024, 1360×768,

1440×900, 1680×1050 &

1920×1080)

HDMI (one in, one

out)

4K 2160p, 1080p, 1

080i, 720p

Audio I/O

Optical Toslink, Stereo

RCA

DTS (movies only), Dolby

Digital Live, Dolby

HDMI, Optical

Toslink, Stereo RCA

DTS (movies only), WMA

Pro, Dolby Digital,Dolby

HDMI (one in, one

out), Optical

Toslink

DTS-HD Master

Digital, Dolby

Surround, Stereo

Surround, Stereo Audio, Dolby

TrueHD, DTS-HD

High Resolution

Audio, Dolby

Digital

Plus, DTS,Dolby

Digital

Online

service

Xbox Live (2002–10) XLink

Kai (2003-present)

Xbox Live

Xbox Live Arcade

Xbox Live Marketplace

Xbox Live Vision (webcam),

headset

Xbox Live Video Marketplace

Windows Live Messenger

Internet Explorer (Xbox Live

Gold required)

VideoKinect (Kinect sensor is no longer

needed)

Xbox Live

Xbox Store

Internet Explorer

Skype

Backward

compatibilit

y

N/A 50% of Xbox Library None[37]

System

software

Xbox Music Mixer

DVD Playback Kit, Xbox

Linux

see Xbox 360 system software Xbox OS

System

software

features

Audio CD playback

[show]

TBA

Consumer

programma

bility

Via Softmods and/or modchips

; Modified Windows

CE 2.x, Linux

Development on PC with XNA

Game Studio($99/year

subscription, binary distribution

with XNA 1.0 Refresh)

TBA

Xbox (console)

The Xbox is a video game console developed by Microsoft. It was released on November 15,

2001, in North America, followed by Australia and Europe in 2002. It was Microsoft's first

foray into the gaming console market. As a sixth-generation console, it competed with

Sony's PlayStation 2, Sega's Dreamcast, and the Nintendo GameCube.

It featured Xbox Live, a fee-based online gaming service that enabled subscribers to

download new content and connect with other players through

a broadband connection.[6][7]

Unlike other online services from Sega and Sony, Xbox Live

had support in the original console design through an integrated Ethernet port. Xbox's

successor, the Xbox 360, was launched in November 2005.

History

In 1998, four engineers from Microsoft's DirectX team, Kevin Bachus, Seamus Blackley, Ted

Hase and DirectX team leader Otto Berkes, disassembled some Dell laptop computers to

construct a prototype Microsoft Windows-based video game console. The team hoped to

create a console to compete with the Sony's upcoming PlayStation 2, which was luring game

developers away from the Windows platform. The team approached Ed Fries, the leader of

Microsoft's game publishing business at the time, and pitched their "DirectX Box" console

based on the DirectX graphics technology developed by Berkes' team. Fries decided to

support the team's idea of creating a Windows DirectX based console.

During development, the original DirectXbox name was shortened to Xbox. Microsoft's

marketing department did not like the Xbox name, and suggested many alternatives. During

focus testing, the Xbox name was left on the list of possible names to demonstrate how

unpopular the Xbox name would be with consumers. However, consumer testing revealed

that Xbox was preferred by far over the other suggested names and "Xbox" became the

official name of the product.

The Xbox was the second console produced by an American company since the Apple

Pippin ceased production in 1997, after the release of the Nuon in 2000. It Microsoft's first

video game console after collaborating with Sega to port Windows CE to the

Dreamcast console. Microsoft repeatedly delayed the console, which was first mentioned

publicly in late 1999 during interviews with Microsoft's then-CEO Bill Gates. Gates stated

that a gaming/multimedia device was essential for multimedia convergence in the new times.

He has even been quoted as saying "if we do not advance, to the next generation, we will

most surely fall behind our competitors (Apple)".

The Xbox was officially announced at the Game Developers Conference on March 10,

2000. Audiences were impressed by the console's technology. At the time of Gates'

announcement, Sega's Dreamcast sales were diminishing and Sony's PlayStation 2 was just

going on sale in Japan. The Xbox was officially unveiled to the public by Gates and guest

professional wrestler The Rock at CES 2001 in Las Vegas on January 3, 2001. Microsoft

announced Xbox's release dates and prices at E3 2001 in May. Most Xbox launch titles were

unveiled at E3, most notably Halo: Combat Evolved and Dead or Alive 3.

Due to the immense popularity of gaming consoles in Japan, Microsoft delayed the release of

the Xbox in Europe to focus on the Japanese video game market. Although delayed, the

European release proved to be more successful than the launch of the Xbox in Japan.

Some of Microsoft's plans proved effective. In preparation for its launch, Microsoft

acquired Bungie and used Halo: Combat Evolved as its launch title. At the time, Golden Eye

007 for the Nintendo 64 had been one of the few hit FPS games to appear on a console, some

of other ones being Perfect Dark and Medal of Honor. Halo: Combat Evolved proved a good

application to drive the Xbox's sales. In 2002, Microsoft made the second place slot in

consoles sold in North America. The Xbox Live service gave Microsoft an early foothold in

online gaming and would help the Xbox become a relevant competitor to other sixth-

generation consoles.

Popular launch games for the console included Dead or Alive 3, Amped: Freestyle

Snowboarding, Halo: Combat Evolved, Fuzion Frenzy, Project Gotham Racing, and Jet Set

Radio Future.

Promotion

In 2002 the Independent Television Commission (ITC) banned a television advertisement for

the Xbox in the United Kingdom after complaints that it was highly distasteful, violent, scary

and upsetting. It depicted a mother giving birth to a small boy who was fired like a projectile

through a hospital window and who aged rapidly as he flew through the air yelling. As he

soared across a large area, he passed quickly through stages of his life as though time was

passing him by. After aging into an old man, he crash-landed into his own grave. Dust and

smoke poured from the grave. The advertisement ended with the slogan Life is short. Play

more.

Discontinuation and successor

The Xbox's successor, the Xbox 360, was officially unveiled announced on May 12, 2005

on MTV and released in North America on November 22, 2005. Nvidia ceased production of

the Xbox's GPU in August 2005, which marked the end of brand-new Xbox production. The

Xbox was discontinued in Japan in 2007 immediately after 360's launch, due to poor sales in

the country. Sales were much better throughout Europe and North America where the console

was discontinued in late 2008 and early 2009, respectively. The last Xbox game in Europe

was Xiaolin Showdown released in June 2007, and the last game in North America

was Madden NFL 09 released in August 2008. Support for out-of-warranty Xbox consoles

was discontinued on March 2, 2009. Support for Xbox Live on the console ended on April

15, 2010.

The Xbox 360 supports a limited number of the Xbox's game library if the player has an

official Xbox 360 Hard Drive. Xbox games were added up until November 2007. Xbox game

saves cannot be transferred to Xbox 360, and the ability to play Xbox games through Xbox

LIVE has been discontinued since April 15, 2010. It is still possible to play Xbox games

with System Link functionality online via both the original console & the Xbox 360 with

tunneling software such as XLink Kai.

Hardware

Xbox was the first video game console to feature a built-in hard disk drive, used primarily

for storing game saves and content downloaded from Xbox Live. This eliminated the need for

separate memory cards (although some older consoles, such as the Amiga CD32 used internal

flash memory and others like the TurboGrafx-CD, Sega CD and Sega Saturn had featured

built-in battery backup memory prior to 2001). An Xbox user could rip music from standard

audio CDs to the hard drive, and these songs were used for the custom soundtracks in some

games.

The Xbox was the first gaming product to feature Dolby Interactive Content-Encoding

Technology, which allows real-time Dolby Digital encoding in game consoles. Previous

game consoles could only use Dolby Digital 5.1 during non-interactive "cut scene" playback.

The Xbox is based on commodity PC hardware and is much larger and heavier than its

contemporaries. This is largely due to a bulky tray-loading DVD-ROM drive and the

standard-size 3.5 inch hard drive. The Xbox has also pioneered safety features, such as

breakaway cables for the controllers to prevent the console from being pulled from the

surface it rests on.

Several internal hardware revisions have been made in an ongoing battle to

discourage modding (hackers continually updated modchip designs in an attempt to defeat

them), to cut manufacturing costs, and to make the DVD-ROM drive more reliable (some of

the early units' drives gave Disc Reading Errors due to the unreliable Thomson DVD-ROM

drives used). Later generation units that used the Thomson TGM-600 DVD-ROM drives and

the Philips VAD6011 DVD-ROM drives were still vulnerable to failure that rendered the

consoles either unable to read newer discs or caused them to halt the console with an error

code usually indicating a PIO/DMA identification failure, respectively. These units were not

covered under the extended warranty.

In 2002 Microsoft and Nvidia entered arbitration over a dispute on the pricing of Nvidia's

chips for the Xbox. Nvidia's filing with the SEC indicated that Microsoft was seeking a

US$13 million discount on shipments for NVIDIA's fiscal year 2002. Microsoft alleged

violations of the agreement the two companies entered, sought reduced chipset pricing, and

sought to ensure that Nvidia fulfill Microsoft's chipset orders without limits on quantity. The

matter was privately settled on February 6, 2003.

Launch-era Xbox gaming units were made in Hungary and the controllers made mostly

in Indonesia.

The Xbox includes a standard AV cable which provides composite

video and monaural or stereo audio to TVs equipped with RCA inputs. European Xboxes also

included an RCA jack to SCART converter block as well as the standard AV cable.

An 8 MB removable solid state memory card can be plugged into the controllers, onto which

game saves can either be copied from the hard drive when in the Xbox dashboard's memory

manager or saved during a game. Most Xbox game saves can be copied to the memory unit

and moved to another console but some Xbox saves are digitally signed. It is also possible to

save an Xbox Live account on a memory unit, to simplify its use on more than one Xbox.

Technical specifications

Controllers

Original Xbox controller

Xbox controller S

The Xbox controller features two analog sticks, a pressure-sensitive directional pad, two

analog triggers, a Back button, a Start button, two accessory slots and s ix 8-bit analog action

buttons (A/Green, B/Red, X/Blue, Y/Yellow, and Black and White buttons). The standard

Xbox controller (also nicknamed the "Fatty" and later, the "Duke") was originally the

controller bundled with Xbox systems for all territories except Japan. The controller has been

criticized for being bulky compared to other video game controllers; it was awarded "Blunder

of the Year" by Game Informer in 2001, a Guinness World Record for the biggest controller

in Guinness World Records Gamer's Edition 2008, and was ranked the second-worst video

game controller ever by IGN editor Craig Harris.

The "Controller S" (codenamed "Akebono"), a smaller, lighter Xbox controller, was

originally the standard Xbox controller only in Japan, designed for users with smaller

hands. The "Controller S" was later released in other territories by popular demand and by

2002 replaced the standard controller in the Xbox's retail package, with the larger original

controller remaining available as an accessory.

Software

Operating system

The Xbox runs a custom operating system which was once believed to be a modified version

of the Windows 2000 kernel. It exposes APIs similar to APIs found in Microsoft Windows,

such as DirectX 8.1. The system software may have been based on the Windows

NT architecture that powered Windows 2000; it is not a modified version of either.

The user interface for the Xbox is called the Xbox Dashboard. It features a media player that

can be used to play music CDs, rip CDs to the Xbox's built-in hard drive and play music that

has been ripped to the hard drive; it also let users manage game saves, music, and

downloaded content from Xbox LIVE, and lets Xbox LIVE users sign in and manage their

account. The dashboard is only available when the user is not watching a movie or playing a

game. It uses many shades of green and black for the user interface, to be consistent with the

physical Xbox color scheme. When the Xbox was released in 2001 the LIVE service was not

online yet, so the dashboard's LIVE feature was unusable.

Xbox LIVE was released in 2002, but in order to access it users had to buy the Xbox LIVE

starter kit containing a headset, a subscription, and supplemental. While the Xbox was still

being supported by Microsoft, the Xbox Dashboard was updated via Xbox LIVE several

times to reduce cheating and add features.

Games

The Xbox launched in North America on November 15, 2001. Its most successful launch

game was Halo: Combat Evolved. Its sequel, Halo 2, is the best-selling Xbox game

worldwide. Although there were several more popular second-party launch titles,

including NFL Fever 2002, Project Gotham Racing, and Dead or Alive 3, the early public

reputation of the Xbox was damaged by the failure of Azurik: Rise of Perathia and other

games designed and marketed by Microsoft.

Although the console gained strong third party support from its inception, many early Xbox

games did not fully use its powerful hardware, with few additional features or graphical

improvements to distinguish them from the PS2 version, thus negating one of the Xbox's

main selling points. Sony countered the Xbox for a short time by temporarily securing

PlayStation 2 exclusives for highly anticipated games such as the Grand Theft

Auto series and Metal Gear Solid 2: Sons of Liberty.

In 2002 and 2003, several releases helped the Xbox gain momentum and distinguish itself

from the PS2. The Xbox Live online service was launched in late 2002 alongside pilot

titles MotoGP, MechAssault and Tom Clancy's Ghost Recon. Several best-selling and

critically praised titles for the Xbox were published, such as Tom Clancy's Splinter

Cell, Ninja Gaiden and LucasArts' Star Wars: Knights of the Old Republic. Take-Two

Interactive's exclusivity deal with Sony was amended to allow Grand Theft Auto III and

its sequels to be published for the Xbox. Many other publishers got into the trend of releasing

the Xbox version alongside the PS2 version, instead of delaying it for months.

In 2004 Halo 2 became the highest-grossing release in entertainment history, making over

$125 million in its first day

and becoming Xbox Live's third killer app after

MechAssault & Tom Clancy's Rainbow Six 3. That year Microsoft made a deal to

put Electronic Arts's popular titles on Xbox Live.

The last game released on the Xbox was Madden NFL 09, on August 12, 2008.

Services

On November 15, 2002, Microsoft launched its Xbox Live online gaming service, allowing

subscribers to play online Xbox games with other subscribers around the world and download

new content directly to the system's hard drive. The online service works only with

a broadband Internet connection. Approximately 250,000 subscribers signed up within two

months of Xbox Live's launch. In July 2004, Microsoft announced that Xbox Live had

reached 1 million subscribers; in July 2005, membership reached two million, and by July

2007 there were more than 3 million subscribers. By May 2009, the number had ballooned to

20 million current subscribers. On February 5, 2010, Marc Whitten posted on gamers

coreblog that Xbox Live support for the original Xbox games would be discontinued as of

April 14, 2010. Services were discontinued on schedule, but a group of 20 gamers continued

to play for almost a month afterwards by simply leaving their consoles on connected to Halo

2. APACHE N4SIR was the final user to play on the original Xbox's Live Service and was

finally disconnected on 2010-05-11 at 01:58 EDT (UTC-4).

Sales

Region Units sold

(as of May 10, 2006) First available

North America 16 million November 15, 2001

Europe 6 million March 14, 2002

Asia & Pacific 2 million February 22, 2002

Worldwide 24 million

On November 15, 2001, Xbox launched in North America and quickly sold out. Its launch in

that region was successful, selling 1.53 million units three months after launch, which is

higher than its successor Xbox 360, as well as the GameCube, PlayStation 3, Wii U, and even

the PlayStation 2 and Wii.

The Xbox has sold 24 million units worldwide as of May 10, 2006, according to

Microsoft. This is divided out to 16 million units sold in North America, six million units in

Europe, and just two million units sold in Asia, Australia, and New Zealand.

The Xbox was almost always behind the PlayStation 2 in terms of sales, although in April

2004, the Xbox outsold the PS2 in the U.S. Despite lagging far behind the PlayStation 2's

sales, the Xbox was overall a success (especially in North America), keeping a steady second

place in the generation sales.

Xbox 360

Microsoft’s Xbox 360 game console is the first of the latest generation of game con-soles.

Historically, game console architecture and design implementations have provided large

discrete jumps in system performance, approximately at five-year intervals. Over the last

several generations, game console systems have increasingly become graphics supercom-

puters in their own right, particularly at the launch of a given game console generation.

The Xbox 360, pictured in Figure 1, contains an aggressive hardware architecture and

imple-mentation targeted at game console workloads. The core silicon implements the

product designers’ goal of providing game developers a hardware platform to implement their

next-gen-eration game ambitions. The core chips include the standard conceptual blocks of

CPU, graph-ics processing unit (GPU), memory, and I/O. Each of these components and their

intercon-nections are customized to provide a user-friendly game console product.

Design principles

One of the Xbox 360’s main design princi-ples is the next-generation gaming principle—

that is, a new game console must provide value to customers for five to seven years. Thus, as

for any true next-generation game console hardware, the Xbox 360 delivers a huge discrete

jump in hardware performance for gaming.

The Xbox 360 hardware design team had to translate the next-generation gaming prin-ciple

into useful feature requirements and next-generation game workloads. For the game

workloads, the designers’ direction came from interaction with game developers, including

game engine developers, middle-ware developers, tool developers, API and dri-ver

developers, and game performance experts, both inside and outside Microsoft.

One key next-generation game feature requirement was that the Xbox 360 system must

implement a 720p (progressive scan) pervasive high-definition (HD), 16:9 aspect ratio screen

in all Xbox 360 games. This fea-ture’s architectural implication was that the Xbox 360

required a huge, reliable fill rate.

Another design principle of the Xbox 360 architecture was that it must be flexible to suit

the dynamic range of game engines and game developers. The Xbox 360 has a balanced

hardware architecture for the software game pipeline, with homogeneous, reallocatable

hardware resources that adapt to different game genres, different developer emphases, and

even to varying workloads within a frame of a game. In contrast, heterogeneous hard-ware

resources lock software game pipeline performance in each stage and are not reallo-catable.

Flexibility helps make the design ―futureproof.‖ The Xbox 360’s three CPU cores, 48 unified

shaders, and 512-Mbyte DRAM main memory will enable developers

A third design principle was programma-bility; that is, the Xbox 360 architecture must be

easy to program and develop software for. The silicon development team spent much time

listening to software developers (we are hardware folks at a software company, after all).

There was constant interaction and iter-ation with software developers at the very beginning

of the project and all along the architecture and implementation phases.

This interaction had an interesting dynam-ic. The software developers weren’t shy about their

hardware likes and dislikes. Likewise, the hardware team wasn’t shy about where next-

generation hardware architecture and design were going as a result of changes in silicon

processes, hardware architecture, and system design. What followed was further iteration on

planned and potential workloads. An important part of Xbox 360 pro-grammability is that the hardware must present the

simplest APIs and programming models to let game developers use hardware resources

effectively. We extended pro-gramming models that developers liked. Because software

developers liked the first Xbox, using it as a working model was nat-ural for the teams. In

listening to developers, we did not repackage or include hardware features that developers did

not like, even though that may have simplified the hard-ware implementation. We considered

the software tool chain from the very beginning of the project. Another major design principle was that the Xbox 360 hardware be optimized for achiev-able

performance. To that end, we designed a scalable architecture that provides the great-est

usable performance per square millimeter while remaining within the console’s system power

envelope. As we continued to work with game devel-opers, we scaled chip implementations to result in

balanced hardware for the software game pipeline. Examples of higher-level implementation

scalability include the num-ber of CPU cores, the number of GPU shaders, CPU L2 size, bus

bandwidths, and main memory size. Other scalable items rep-resented smaller optimizations

in each chip. Hardware designed for games Figure 2 shows a top-level diagram of the Xbox 360 system’s

core silicon components. The three identical CPU cores share an 8-way set-associative, 1-

Mbyte L2 cache and run at 3.2 GHz. Each core contains a complement of four-way single-

instruction, multiple data (SIMD) vector units.1 The CPU L2 cache, cores, and vector units

are customized for Xbox 360 game and 3D graphics workloads.

The front-side bus (FSB) runs at 5.4 Gbit/pin/s, with 16 logical pins in each direction, giving

a 10.8-Gbyte/s read and a 10.8-Gbyte/s write bandwidth. The bus design and the CPU L2

provide added sup-port that allows the GPU to read directly from the CPU L2 cache. As Figure 2 shows, the I/O chip supports abundant I/O components. The Xbox media audio

(XMA) decoder, custom-designed by Microsoft, provides on-the-fly decoding of a large

number of compressed audio streams in hardware. Other custom I/O features include

Figure: xbox 360 block diagram

CPU I/O

chip

Core 0 Core 1 Core 2

L1D L1I L1D L1I L1D L1I

1 Mbyte L2

Memory GPU decode

r

MC

1

BIU/IO interface

XM

A

512 Mbyte

DRAM 3D core

SM

C

MC

0

10 Mbytes Video

Analog

EDRAM out

chip

BIU Bus interface unit

MC Memory controller

HDD Hard disk drive

MU Memory unit

IR Infrared receiver

SMC System management controller

XMA Xbox media audio

The GPU 3D core has 48 parallel, unified shaders. The GPU also includes 10 Mbytes of

embedded DRAM (EDRAM), which runs at 256 Gbytes/s for reliable frame and z-buffer

bandwidth. The GPU includes interfaces between the CPU, I/O chip, and the GPU internals. The 512-Mbyte unified main memory con-trolled by the GPU is a 700-MHz graphics-

double-data-rate-3 (GDDR3) memory, which operates at 1.4 Gbit/pin/s and provides a total

main memory bandwidth of 22.4 Gbytes/s. The DVD and HDD ports are serial ATA (SATA) interfaces. The analog chip drives the

HD video out.

CPU chip

Figure 3 shows the CPU chip in greater detail. Microsoft’s partner for the Xbox 360 CPU is

IBM. The CPU implements the Pow-erPC instruction set architecture,2-4

with the VMX

SIMD vector instruction set (VMX128) customized for graphics workloads. The shared L2 allows fine-grained, dynamic allocation of cache lines between the six threads. Commonly, game workloads significantly vary in working-set size. For example, scene man-agement requires walking larger, random-miss-dominated data structures, similar to database searches. At the same time, audio, Xbox proce-dural synthesis (described later), and many other game processes that require smaller working sets can run concurrently. The shared L2 allows workloads needing larger working sets to allo-cate significantly more of the L2 than would be available if the system used private L2s (of the same total L2 size) instead.

The CPU core has two-per-cycle, in-order instruction issuance. A

separate vector/scalar issue queue (VIQ) decouples instruction

issuance between integer and vector instruc-tions for nondependent

work. There are two symmetric multithreading (SMT),5 fine-grained

hardware threads per core. The L1 caches include a two-way set-

associative, 32-Kbyte L1 instruction cache and a four-way set-

associative, 32-Kbyte L1 data cache. The write-through data cache

does not allocate cache lines on writes.

The integer execution pipelines include branch, integer, and load/store units. In addition,

each core contains an IEEE-754-compliant scalar floating-point unit (FPU), which includes

single- and double-precision support at full hardware throughput of one operation per cycle

for most operations. Each core also includes the four-way SIMD VMX128 units: floating-

point (FP), per-mute, and simple. As the name implies, the VMX128 includes 128 registers,

of 128 bits each, per hardware thread to maximize throughput. The VMX128 implementation includes an added dot product instruction, common in graphics

applications. The dot product implementation adds minimal latency to a multiply-add by

simplifying the rounding of intermediate multiply results. The dot prod-uct instruction takes

far less latency than dis-crete instructions. Another addition we made to the VMX128 was direct 3D (D3D) compressed data for-

mats,6-8

the same formats supported by the GPU. This allows graphics data to be gener-ated

in the CPU and then compressed before being stored in the L2 or memory. Typical use of the

compressed formats allows an approx-imate 50 percent savings in required band-width and

memory footprint

CPU data streaming

In the Xbox, we paid considerable atten-tion to enabling data-streaming workloads, which

are not typical PC or server workloads. We added features that allow a given CPU core to

execute a high-bandwidth workload (both read and write, but particularly write), while

avoiding thrashing its own cache and the shared L2. First, some features shared among the CPU cores help data streaming. One of these is 128-

byte cache line sizes in all the CPU L1 and L2 caches. Larger cache line sizes increase FSB

and memory efficiency. The L2 includes a cache-set-locking functionality, common in

embedded systems but not in PCs. Specific features that improve streaming bandwidth for writes and reduce thrashing include

the write-through L1 data caches. Also, there is no write allocation of L1 data cache lines

when writes miss in the L1 data cache. This is important for write streaming because it keeps

the L1 data cache from being thrashed by high bandwidth transient write-only data streams. We significantly upgraded write gathering in the L2. The shared L2 has an uncached unit

for each CPU core. Each uncached unit has four noncached write-gathering buffers that allow

multiple streams to concurrently gath-er and dump their gathered payloads to the FSB yet

maintain very high uncached write-streaming bandwidth. The cacheable write streams are gathered by eight nonsequential gathering buffers per CPU

core. This allows programming flexibility in the write patterns of cacheable very high

bandwidth write streams into the L2. The write streams can randomly write within a window

of a few cache lines without the writes backing up and caus-ing stalls. The cacheable write-

gathering buffers effectively act as a bandwidth compression scheme for writes. This is

because the L2 data arrays see a much lower bandwidth than the raw bandwidth required by a

program’s store pat-tern, which would have low utilization of the L2 cache arrays. Data

transformation workloads commonly don’t generate the data in a way that allows sequential

write behavior. If the write gathering buffers were not present, software would have to

effectively gather write data in the register set before storing. This would put a large amount

of pressure on the number of reg- isters and increase latency (and thus through-put) of inner

loops of computation kernels.

We applied similar customization to read streaming. For each CPU core, there are eight

outstanding loads/prefetches. A custom prefetch instruction, extended data cache block touch

(xDCBT), prefetches data, but delivers to the requesting CPU core’s L1 data cache and never

puts data in the L2 cache as regular prefetch instructions do. This modifi-cation seems minor,

but it is very important because it allows higher bandwidth read streaming workloads to run

on as many threads as desired without thrashing the L2 cache. Another option we considered

for read streaming would be to lock a set of the L2 per thread for read streaming. In that case,

if a user wanted to run four threads concurrently, half the L2 cache would be locked down,

hurting workloads requiring a large L2 working-set size. Instead, read streaming occurs

through the L1 data cache of the CPU core on which the given thread is operating, effectively

giv-ing private read streaming first in, first out (FIFO) area per thread. A system feature planned early in the Xbox 360 project was to allow the GPU to directly

read data produced by the CPU, with the data never going through the CPU cache’s back-ing

store of main memory. In a specific case of this data streaming, called Xbox procedur-al

synthesis (XPS), the CPU is effectively a data decompressor, procedurally generating

geometry on-the-fly for consumption by the GPU 3D core. For 3D games, XPS allows a far

greater amount of differentiated geometry than simple traditional instancing allows, which is

very important for filling large HD screen worlds with highly detailed geometry. We added two features specifically to sup-port XPS. The first was support in the GPU and

the FSB for a 128-byte GPU read from the CPU. The other was to directly lower

communication latency from the GPU back to the CPU by extending the GPU’s tail pointer

write-back feature. Tail pointer write-back is a method of con-trolling communication from the GPU to the

CPU by having the CPU poll on a cacheable location, which is updated when a GPU

instruction writes an update to the pointer. The system coherency scheme then updates the

polling read with the GPU’s updated

HOT CHIPS 17

c Core 2

Core 1 L1I

Core 0 L1I 32 Instruction unit

Kbytes

32 Instruction unit L1D

L1I

Load/

32 Instruction unit Kbytes

Branch VIQ

Int 32

L1D Store

Kbytes

Branch VIQ

Int Load/

32 Kbytes

L1D Store

Branch VIQ Int Load/

32 Kbytes

Store

Kbytes

VS

U

VMX VMX VMX FPU MMU

VS

U VMX VMX FP D3Dpermcompressedsimp data,

VMX MMU

VS

U

VMX VMX FP perm simp FPU VMX stores to L2

VMX FPU

MMU

FP perm simp

xDCBT 128-byte prefetch

around L2, into L1 data cache

L2 Node crossbar/queuing

Uncached

L2 L2 Non-sequential gathering,

PIC

L2 data locked set in L2

Uncached

Unit2 directory directory

Uncached

Unit2

Unit2

Test, Bus interface

debug,

clocks,

Temperature

sensor.

Figure :- CPU cached data-streaming example.

pointer value. Tail write-backs reduce com-munication latency compared to using interrupts.

We lowered GPU-to-CPU com-munication latency even further by imple-menting the tail

pointer’s backing-store target on the CPU die. This avoids the round-trip from CPU to

memory when the GPU point-er update causes a probe and castout of the CPU cache data,

requiring the CPU to refetch the data all the way from memory. Instead the refetch never

leaves the CPU die. This lower latency translates into smaller streaming FIFOs in the L2’s

locked set.

A previously mentioned feature very impor-tant to XPS is the addition of D3D com-pressed

formats that we implemented in both the CPU and the GPU. To get an idea of this feature’s

usefulness, consider this: Given a typ-ical average of 2:1 compression and an XPS-targeted 9

Gbytes/s FSB bandwidth, the CPU cores can generate up to 18 Gbytes/s of effec-tive

geometry and other graphics data and ship it to the GPU 3D core. Main memory sees none of

this data traffic (or footprint). CPU cached data-streaming example Figure 4 illustrates an example of the Xbox 360 using its data-streaming features for an XPS

workload. Consider the XPS workload, acting as a decompression kernel running on one or

more CPU SMT hardware threads. First, the XPS kernel must fetch new, unique data from

memory to enable generation of the given piece of geometry. This likely includes world

space coordinate data and specific data to make each geometry instance unique. The XPS

kernel prefetches this read data during a previous geometry generation iteration to cover the

fetch’s memory latency. Because none of the per-instance read data is typical-ly reused

between threads, the XPS kernel fetches it using the xDCBT prefetch instruc-tion around the

L2, which puts it directly into the requesting CPU core’s L1 data cache. Prefetching around

the L2 separates the read data stream from the write data stream, avoid-ing L2 cache

thrashing. Figure 4 shows this step as a solid-line arc from memory to Core 0’s L1 data

cache. The XPS kernel then crunches the data, primarily using the VMX128 computation ability to

generate far more geometry data than the amount read from memory. Before the data is

written out, the XPS kernel com-presses it, using the D3D compressed data formats, which

offer simple trade-offs between number of bits, range, and precision. The XPS kernel stores

these results as gener-ated to the locked set in the L2, with only minimal attention to the write

access pattern’s randomness (for example, the kernel places write accesses within a few

cache lines of each other for efficient gathering). Furthermore, because of the write-through

and no-write-allocate nature of the L1 data caches, none of the write data will thrash the L1

data cache of the CPU core. The diagram shows this step as a dashed-line arc from load/store

in Core 0 to the locked set in L2. Once the CPU core has issued the stores, the store data sits in the gathering buffers wait-ing

for more data until timed out or forced out by incoming write data demanding new 64-byte

ranges. The XPS output data is writ-ten to software-managed FIFOs in the L2 data arrays in a

locked set in the L2 (the unshaded box in Figure 4). There are multiple FIFOs in one locked

set, so multiple threads can share one L2 set. This is possible within 128 Kbytes of one set

because tail pointer write-back com-munication frees completed FIFO area with lowered

latency. Using the locked set is impor-tant; otherwise, high-bandwidth write streams would

thrash the L2 working set. Next, when more data is available to the GPU, the CPU notifies the GPU that the GPU

can advance within the FIFO, and the GPU performs 128-byte reads to the FSB. This

step is shown in the diagram as the dot-ted-line arc starting in the L2 and going to the

GPU. The GPU design incorporates special features allowing it to read from the FSB,

in contrast with the normal GPU read from main memory. The GPU also has an added

128-byte fetch, which enables maximum FSB and L2 data array utilization. The two final steps are not shown in the diagram. First, the GPU uses the corre-

sponding D3D compressed data format sup-port to expand the compressed D3D

formats into single-precision floating-point formats native to the 3D core. Then, the

GPU com-mands tail pointer write-backs to the CPU to indicate that the GPU has

finished reading data. This tells the streaming FIFOs’ CPU software control that the

given FIFO space is now free to be written with new geometry or index data. Figure 5 shows a photo of the CPU die, which contains 165 million transistors in an IBM

second-generation 90-nm silicon-on-insulator (SOI) enhanced transistor process.

Figure 5. Xbox 360 CPU die photo (courtesy of IBM).

Graphics processing unit

The GPU is the latest-generation graphics processor from ATI. It runs at 500 MHz and

consists of 48 parallel, combined vector and scalar shader ALUs. Unlike earlier graphics

engines, the shaders are dynamically allocat-ed, meaning that there are no distinct vertex or

pixel shader engines—the hardware auto-matically adjusts to the load on a fine-grained basis.

The hardware is fully compatible with D3D 9.0 and High-Level Shader Language (HLSL).

The ALUs are 32-bit IEEE 754 floating-point ALUs, with relatively common graphics

simplifications of rounding modes, denor-malized numbers (flush to zero on reads), NaN

handling, and exception handling. They are capable of vector (including dot product) and

scalar operations with single-cycle throughput—that is, all operations issue every cycle. The

superscalar instructions encode vec-tor, scalar, texture load, and vertex fetch with-in one

instruction. This allows peak processing of 96 shader calculations per cycle while fetching

textures and vertices. Feeding the shaders are 16 texture fetch engines, each capable of producing a filtered result

in each cycle. In addition, there are 16 programmable vertex fetch engines with built-in

tessellation that the system can use instead of CPU geometry generation. Finally, there are 16

interpolators in dedicated hardware. The render back end can sustain eight pix-els per cycle or 16 pixels per cycle for depth and

stencil-only rendering (used in z-prepass or shadow buffers). The dedicated z or blend logic

antialiasing and transparency. The z-prepass is a technique that performs a first-pass

rendering of a command list, with no ren-dering features applied except occlusion

determination. The z-prepass initializes the z-buffer so that on a subsequent rendering pass

with full texturing and shaders applied, dis-carded pixels won’t spend shader and textur-ing

resources on occluded pixels. With modern scene depth complexity, this technique signif-

icantly improves rendering performance, espe-cially with complex shader programs.

-buffer,

six shader operations, and two texture fetches and can sustain this at eight pixels per cycle.

This blazing fill rate enables the Xbox 360 to deliver HD-resolution rendering simul-

taneously with many state-of-the-art effects that traditionally would be mutually exclusive

because of fill rate limitations. For example, games can mix particle, high-dynamic-range

(HDR) lighting, fur, depth-of-field, motion blur, and other complex effects. For next-generation geometric detail, shad-ing, and fill rate, the pipeline’s front end can

process one triangle or vertex per cycle. These are essentially full-featured vertices (rather

than a single parameter), with the practical limitation of required memory bandwidth and

storage. To overcome this limitation, sev-eral compressed formats are available for each data

type. In addition, XPS can transiently generate data on the fly within the CPU and pass it

efficiently to the GPU without a main memory pass. The EDRAM removes the render target and z-buffer fill rate from the bandwidth equation.

The EDRAM resides on a separate die from the main portion of GPU logic. The EDRAM die

also contains dedicated alpha blend, z-test, and antialiasing logic. The inter-face to the

EDRAM macro runs at 256 Gbytes/s: (8 pixels/cycle + 8 z- + write)

- The GPU supports several pixel depths; 32 bits per pixel (bpp) and 64 bpp are the most

common, but there is support for up to 128 bpp for multiple-render-target (MRT) or floating-

point output. MRT is a graphics technique of outputting more than one piece of data per

sample to the effective frame buffer, interleaved efficiently to minimize the performance

impact of having more data. The data is used later for a variety of advanced graphics effects.

To optimize space, the GPU supports 32-bpp and 64-bpp HDR lighting formats.

Command

Vertex processor

FSB cache Vertex assembly/

Texture tesselator

cache Sequencer

Hi-Z Interpolators

Main die Bus Shader complex

Shader export

interface unit

Blending interface

Me

m 1

MC

1

I/O controller PCI-E I/O

inte

rfa

c

e High-speed

Graphics I/O bus

AA

+A

Z

Me

mo

ry

10-Mbyte

0em

M

C0M

EDRAM

Display

DRAM die

Video

Figure 6. GPU block diagram.

whole process inserted in the traditional graph-ics pipeline for binning the geometry into a

large number of bins. Handling the bins in a high-performance manner is complicated (for

exam-ple, overflow cases, memory footprint, and bandwidth). Because the GPU’s EDRAM

usu-ally requires only a couple of bins, bin handling is greatly simplified, allowing more-

optimal hardware-software partitioning. With a binning architecture, the full com-mand list must be presented before rendering. The

hardware uses a few tricks to speed this process up. Rendering increasingly relies on a z-

prepass to prepare the z-buffer before exe-cuting complex pixel shader algorithms. We take

advantage of this by collecting object extent information during this pass, as well as priming

a full-resolution hierarchical z-buffer. We use the extent information to set flags to skip

command list sections not needed with-in a tile. The full-resolution hi-z buffer retains its state

between tiles. In another interesting extension to normal D3D, the GPU supports a shader export fea-ture

that allows data to be output directly from the shader to a buffer in memory. This lets the

GPU serve as a vector math engine if needed, as well as allowing multipass shaders. The

latter can be useful for subdivision sur-faces. In addition, the display pipeline includes an in-

line scaler that resizes the frame buffer on the fly as it is output. This feature allows games to

pick a rendering resolution to work with and then lets the display hardware make the best

match to the display resolution.

As Figure 6 shows, the GPU consists of the following blocks:

• Bus interface unit. This interface to the FSB handles CPU-initiated transactions, as well

as GPU-initiated transactions such as snoops and L2 cache reads.

• I/O controller. Handles all internal mem-ory-mapped I/O accesses, as well as trans-

actions to and from the I/O chip via the two-lane PCI-Express bus (PCI-E).

• Memory controllers (MC0, MC1). These 128-byte interleaved GDDR3 memory

controllers contain aggressive address tiling for graphics and a fast path to min-imize

CPU latency. • Memory interface. Memory crossbar and buffering for non-CPU initiators (such as

graphics, I/O, and display).

Figure 7. Xbox 360 GPU “parent” die

(courtesy of Taiwan Semiconductor Manufacturing Co.).

Figure 8. Xbox 360 GPU EDRAM (“daughter”) die (courtesy of NEC Electronics).

• Graphics. This block, the largest on the chip, contains the rendering engine. High-speed I/O bus. This bus between the graphics core and the EDRAM die is a chip-to-

chip bus (via substrate) operat-ing at 1.8 GHz and 28.8 Gbytes/s. When multisample

antialiasing is used, only pixel center data and coverage informa- tion is transferred and

then expanded on the EDRAM die. • Antialiasing and Alpha/A (AA+AZ). Han-dles pixel-to-sample expansion, as well as z-test

and alpha blend. • Display.

Figures 7 and 8 show photos of the GPU ―parent‖ and EDRAM (―daughter‖) dies. The

parent die contains 232 million transistors in a TSMC 90-nm GT. The EDRAM die con-tains

100 million transistors in an NEC 90-nm process.

Architectural choices

The major choices we made in designing the Xbox 360 architecture were to use chip

multiprocessing (CMP), in-order issuance cores, and EDRAM. Chip multiprocessing

Our reasons for using multiple CPU cores on one chip in Xbox 360 was relatively

straightforward. The combination of power consumption and diminishing returns from

instruction-level parallelism (ILP) is driving the industry in general to multicore. CMP is a

natural twist on traditional symmetric mul-tiprocessing (SMP), in which all the CPU cores

are symmetric and have a common view of main memory but are on the same die ver-sus

separate chips. Modern process geometries afford hardware designers the flexibility of CMP,

which was usually too costly in die area previously. Having multiple cores on one chip is

more cost-effective. It enables shared L2 implementation and minimizes communica-tion

latency between cores, resulting in high-er overall performance for the same die area and

power consumption. In addition, we wanted to optimize the architecture for the workload, optimize in-game

utilization of silicon area, and keep the system easy to program. These goals made CMP a

good choice for several reasons: First, for the game workload, both integer and floating-point performance are impor-tant.

The high-level game code is generally a database management problem, with plenty of

object-oriented code and pointer manipu-lation. Such a workload needs a large L2 and high

integer performance. The CMP shared L2 with its fine-grained, dynamic allocation

means this workload can use a large working set in the L2 while running. In addition, sev-eral

sections of the application lend themselves well to vector floating-point acceleration. Second, to optimize silicon area, we can take advantage of two factors. To start with, we

are presenting a stable platform for the product’s lifetime. This means tools and pro-

gramming expertise will mature significantly, so we can rely more on generating code than

optimizing performance at runtime. More-over, all Xbox 360 games (as opposed to Xbox

games from Microsoft’s first game console, which are emulated on Xbox 360) are com-piled

from scratch and optimized for the cur-rent microarchitecture. We don’t have the problem of

running legacy, but compatible, instruction set architecture executables that were compiled

and optimized for a completely different microarchitecture. This problem has significant

implications for CPU microarchi-tectures in PC and server markets. Third, although we knew multicore was the way to go, the tools and programming exper-

tise for multithread programming are certain-ly not mature, presenting a problem for our goal

of keeping programming easy. For the types of workloads present in a game engine, we could

justify at most six to eight threads in the system. The solution was to adapt the ―more-but-

simpler‖ philosophy to the CPU core topology. The key was keeping the num-ber of

hardware threads limited, thus increas-ing the chance that they would be used effectively. We

decided the best approach was to tightly couple dedicated vector math engines to integer

cores rather than making them autonomous. This keeps the number of threads low and allows

vector math routines to be opti-mized and run on separate threads if necessary.

In-order issuance cores

The Xbox 360 CPU contains three two-issue, in-order instruction issuance cores. Each core

has two SMT hardware threads, which support fine-grained instruction issuance. The cores

allow out-of-order execution in the com-mon cases of loads and vector/floating-point versus

integer instructions. Loads, which are treated as prefetches, don’t stall until a load

dependency is present. Vector and floating-point operations have their own, decoupled

vector/float issue queue (VIQ), which decou- ples vector/floating point versus integer

issuance in many cases. We had several reasons for choosing in-order issuance. First, the die area required by in-

order-issuance cores is less than that of out-of-order-issuance cores. In-order cores sim-plify

issue logic considerably. Although not directly a big area user, out-of-order issue logic can

consume extra area because it requires additional pipeline stages to meet clock peri-od

timing. Further, common implementa-tions of out-of-order issuance and completion use

rename registers and completion queues, which take significant die area.

Second, in-order implementation is more power efficient than out-of-order implemen-

tation. Keeping power levels manageable was a major issue for the design team. All the addi-

tional die area required for out-of-order issuance consumes power. Out-of-order cores

commonly increase performance because their issuance, tracking, and completion enable

deeper speculative instruction execution. This deeper speculation means wasted power since

whole execution strings are often thrown away. Xbox 360 execution does speculate but to a

lesser degree. Third, the Xbox 360’s two SMT hardware threads per core keep the execution pipelines

more fully utilized than they are in traditional in-order designs. This helps keep the execution

pipelines busy without out-of-order issuance. Finally, in-order design is simpler, aiding design and implementation. Simplicity also

makes performance more predictable, simpli-fying programming and tool optimizations.

EDRAM HD, alpha blending, z-buffering, antialias-ing, and HDR pixels take a heavy toll on mem-

ory bandwidth. Although more effects are being achieved in the shaders, postprocessing

effects still require a large pixel-depth com-plexity. Also as texture filtering improves, texel

fetches can consume large amounts of memo-ry bandwidth, even with complex shaders. One approach to solving this problem is to use a wide external memory interface. This limits

the ability to use higher-density mem-ory technology as it becomes available, as well as

requiring compression. Unfortunately, any compression technique must be lossless, which

means unpredictable—generally not good for game optimization. In addition, the required

bandwidth would most likely require using a second memory controller in the CPU itself,

rather than having a unified memory architecture, further reducing sys-tem flexibility. EDRAM was the logical alternative. It has the advantage of completely removing the ren-

der target and the z-buffer bandwidth from the main-memory bandwidth equation. In

addition, alpha blending and z-buffering are read-modify-write processes, which further

reduce the efficiency of memory bandwidth consumption. Keeping these processes on-chip

means that the remaining high-band-width consumers—namely, geometry and texture—are

now primarily read processes. Changing the majority of main-memory bandwidth to read

requests increases main-memory efficiency by reducing wasted mem-ory bus cycles caused

by turning around the bidirectional memory buses.

Software

By adopting SMP and SMT, we’re using standard parallel models, which keep things simple.

Also, the uni-fied memory architecture allows flexible use of memory resources.

Our operating system opens all three cores to game developers to program as they wish. For

this, we provide standard APIs including Win32 and OpenMP, as well as D3D and HLSL.

Devel-opers can also bypass these and write their own CPU assembly and shader microc-ode,

referred to in the game industry as ―to the metal‖ programming. We provide standard tools including XNA-based tools Performance Investigator (PIX) and

Xbox Audio Cre-ation Tool (XACT). XNA is Microsoft’s game develop-ment platform,

which devel-opers of PC and Xbox 360 games (as well as other plat-forms) can use to

minimize cross-platform development costs.11

PIX is the graphics profiler and debugger. It

uses per-formance counters embedded in the CPU and GPU and architectural simulators to

provide performance feedback.

The Xbox 360 development environment is familiar to most programmers. Figure 9 shows

a screen shot from the XNA Studio Integrat-ed Development Environment (IDE), a ver-sion

of Visual Studio with additional features for game developer teams. Programmers use IDE

for building projects and debugging, including debugging of multiple threads. When stepping

through source code, pro-grammers find the instruction set’s low-level details completely

hidden, but when they open the disassembly window, they can see that PowerPC code is

running. Other powerful tools that help Xbox 360 developers maximize productivity and per-

formance include CPU profilers, the Visual C++ 8.0 compiler, and audio libraries. These

tools and libraries let programmers quickly exploit the power of Xbox 360 chips and then

help them code to the metal when necessary.

Xbox 360 was launched to customers in the US, Canada, and Puerto Rico on 22 November,

2005. Between then and the end of 2005, it launched in Europe and Japan. Dur-ing the first quarter of 2006, Xbox 360 has been launched in Central and South America, Southeast Asia, Australia, and New Zealand. Xbox 360 implemented a number of firsts and/or raised the bar for performance for users of PC and game console machines for gam- ing. These include

• the first CMP implementation with more than 2 cores (3); • the highest frequency and bandwidth CPU frontside bus (5.4 Gbps and 21.6 GB/s); • the first CMP chip with shared L2; • the first game console with SMT; • the first game console with GPU-unified shader architecture; and • the first game console with MCM GPU/EDRAM die implementation.

The Xbox 360 core chipset contains approximately 500 M transistors. It is the most complex,

highest performance consumer electronic product shipping today and pre-sents a large

discrete jump in 3D graphics and gaming performance.

Xbox One

Xbox One is a video game console developed and marketed by Microsoft. Announced on

May 21, 2013, it is the successor to theXbox 360 and is the third console in the Xbox

family.[6]

It directly competes with Sony's PlayStation 4 and Nintendo's Wii U as part of

the eighth generation of video game consoles.[14][15]

Xbox One was released across North

America, several European markets, Australia, and New Zealand on November 22,

2013,[2]

and is scheduled for release in 26 other markets, including Japan, the remaining

European markets, and the Middle East, sometime in September 2014.[16]

Microsoft and

various publications have classified the device as an "all-in-one entertainment

system",[17][18][19]

making it a competitor to other digital media players such as the Apple

TV and the Google TV platforms.

Moving away from the Xbox 360's PowerPC-based architecture and back into

the x86 architecture used in the first Xbox, the console features an AMD processor built

around the x86-64 instruction set. Xbox One places an increased emphasis on entertainment

integration, offering the ability to overlay live television programming from an existing set-

top box, split-screen multitasking ofapplications, and improved second screen support. The

console includes a newly upgraded Kinect motion sensing peripheral, previously an optional

attachment for the Xbox 360. Microsoft is emphasizing the Kinect's integration with Xbox

One through features such as a built-in Skype client for videoconferencing, user recognition

and tracking, and the ability to use voice commands and gestures to navigate the

console's user interface. New gaming functionality includes an expanded Xbox Live service,

improved Kinect functionality, cloud computing, the ability to automatically record and share

video highlights from gameplay, and support for live streaming gameplay online.

Upon its unveiling, Xbox One was criticized for its initial digital rights management policies

(including a requirement for a periodic connection to the internet, and ambiguous restrictions

on the resale and sharing of previously-purchased games), along with Kinect usage

requirements and higher price than its competitors. In response to the criticism, Microsoft

dropped these restrictions prior to releasing the console.

History

Xbox One is the successor to Xbox 360, Microsoft's previous video game console, which was

introduced in 2005 as part of the seventh generation of video game consoles. As of June

2013, it remains in production by Microsoft, having received a number of small hardware

revisions to reduce the unit's size and improve its reliability. In 2010, Microsoft's Chris Lewis

stated that the 360 was about "halfway" through its lifecycle; this was aided by the

introduction of the Kinect device that year which Lewis stated would extend the lifecycle by

five years.

Initial hardware for the 360's successor, commonly referred to by the industry as the "Xbox

720", was reportedly in hands of developers as early as May 2011. The official developer kit

was codenamed Durango, and appeared to be available to developers by mid-2012. Leaked

documents suggested that the new console would include an improved Kinect device, cloud

access to games and media, integration with phone and tablet devices, and technology to

provide players heads-up displays on glasses worn by the player, codenamed "Fortaleza";

Microsoft did not comment on these reported features. Similar, leaked design documents also

suggested that Microsoft was seeking to eliminate the ability to play used games, though

Microsoft later clarified they were still reviewing the design and were "thinking about what is

next and how we can push the boundaries of technology like we did with Kinect", but did not

comment on the validity of the information.

The console was publicly unveiled under the name Xbox One on May 21, 2013 in a press

conference designed to cover the unit's broad multimedia and social capabilities. A second

press event for the console was held during E3 on June 10, 2013, focusing on its video game-

oriented functionality. At that time, Microsoft announced that the console would release in 21

different markets at launch, but this was later amended down to 13. The change, which

pushed the release date for the other 8 markets to 2014, was attributed to unforeseen

complexity in localizing the new Kinect peripheral.

Hardware

Xbox One's exterior casing consists of a two-tone "liquid black" finish; with half finished in a

matte grey, and the other in a glossier black. The design was intended to evoke a more

entertainment-oriented and simplified look than previous iterations of the console; among

other changes, the LED rings used by Xbox 360 are replaced by a glowing white Xbox logo

used to communicate the system's status to the user.

It is powered by an AMD "Jaguar" Accelerated Processing Unit (APU) with two quad-

core modules totaling eight x86-64 cores clocked at 1.75 GHz , and

8 GB of DDR3 RAM with a memory bandwidth of 68.3 GB/s.The memory subsystem also

features an additional 32 MB of "embedded static" RAM, or ESRAM, with a memory

bandwidth of 109 GB/s.Eurogamer has been told that for simultaneous read and write

operations the ESRAM is capable of a theoretical memory bandwidth of 192 GB/s and that a

memory bandwidth of 133 GB/s has been achieved with operations that involvedalpha

transparency blending.The system includes a 500 GB non-replaceable hard drive, and a Blu-

ray Disc optical drive.About 362 GB of hard drive space is available for the storage of

games; support for external drives will be added in a future update, scheduled to come in

April 2014.

It was reported that 3 GB of RAM would be reserved for the operating system and utility

software, leaving 5 GB for games. The graphics processing unit (GPU) is based on an

AMD GCN architecture with 12 compute units, which have a total of 768 cores, running at

853 MHz providing an estimated peak theoretical power of 1.31 TFLOPS. For networking,

Xbox One supports Gigabit Ethernet, 802.11n wireless, and Wi-Fi Direct.

Xbox One supports 4K resolution (3840×2160) (2160p) video output and 7.1 surround

sound. Yusuf Mehdi, corporate vice president of marketing and strategy for Microsoft, has

stated that there is no hardware restriction that would prevent games from running at 4K

resolution.[49]

Unlike the Xbox 360, the Xbox One does not support 1080i and

otherinterlaced resolutions. Xbox One supports HDMI 1.4 for both input and output, and does

not support composite orcomponent video.

The console can monitor its internal temperature and adjust accordingly to

prevent overheating; alongside increasing fan speed, additional measures can be taken,

including forcing the hardware to run in a lower power state—a feature that was not present

on Xbox 360. Restricting power consumption lowers maximum performance, but the setting

would be intended as a last resort to prevent permanent hardware damage.

Controller

Xbox One's controller maintains the overall layout found in the Xbox 360's design.

The directional pad has been changed to a four-way design, and the battery compartment is

slimmer. Menu and View buttons have replaced the Start and Back buttons.[53]

Each trigger

features independent rumble motors called "Impulse Triggers", which allows developers to

program directional vibration. One trigger can be made to vibrate when firing a gun, or both

can work together to create feedback that indicates the direction of an incoming

hit.[54]

Consumers who Pre-ordered the Xbox One, "Day One Edition" included controllers

that had the words "Day One 2013" engraved in the center of the controller.Microsoft

invested over $100 million into refining the controller design for the Xbox One.

Kinect

Xbox One ships with an updated version of Kinect for motion tracking and voice recognition;

the new Kinect uses a 1080p wide-angle time-of-flight camera (in comparison to the

VGA resolution of the previous version), and processes 2 gigabits of data per second to read

its environment. The new Kinect has greater accuracy over its predecessor, can track up to 6

skeletons at once, perform heart rate tracking, track gestures performed with an Xbox One

controller, and scan QR codes to redeem Xbox Live gift cards. The Kinect microphone

remains active at all times by default so it can receive voice commands from the user when

needed, even when the console is in sleep mode (so it can be awakened with a command).

As was the case on the Xbox 360, Kinect usage is optional, and privacy settings are available

for adjusting how the sensor operates.

A Windows-compatible version of the new Kinect is scheduled to be released in Summer

2014.

Software and services

Media inter-connectivity

Similarly to Windows 8, Xbox One can snap applications (such as music, video, Skype,

and Internet Explorer ) to the side of the screen as a form of multitasking. Xbox One can also

serve as a pass-through for an existing television set-top box over HDMI. This functionality

allows users to watch live TV from their existing provider through the console, and access

features such as show recommendations, an electronic program guide (branded

as OneGuide), and voice commands. The set-top box is controlled by the console by either

using an I blaster in the Kinect sensor, or the HDMI-CEC protocol. On launch, OneGuide is

only compatible with television providers in the United States.

Voice control

The console features a similar, albeit richer set of voice control abilities than those found in

the first generation Kinect, allowing the user to control Xbox functions via voice command.

Users can also initiate conversations through Skype.

Operating system

The device reportedly runs three operating systems: Xbox OS, an OS based on the Windows

kernel, and another OS that allows the other two operating systems to communicate by

virtualisation (as a hypervisor). This integration allows features like snapped Skype calls

while in game.

The Windows kernel on the Xbox is not compatible with standard Windows programs,

though developers will be able to port them over with little effort.

Xbox Live

Microsoft have stated that the Xbox Live service has been scaled up to use 300,000 servers

for Xbox One users, but have not stated how many of the servers are physical and how many

are virtual. Cloud storage is available to save music, films, games and saved content and

developers are able to use Live servers (along with the Windows Azure cloud

computing platform) to offer dynamic changes to players within their game. The service is

still be subscription-based. The friends list has been expanded to 1,000 friends .

SmartGlass

Xbox SmartGlass provides extended functionality on Xbox One, allowing devices

running Windows Phone, Windows 8, iOS and Android to be used as a "second screen." A

demo during the E3 press conference demonstrated its use for setting up a multiplayer match

in another game in the background on a tablet while playing another game on the television.

Recording and streaming

Xbox Live Gold subscribers can use the Upload Studio app to edit and share clips from the

last five minutes of gameplay footage that is automatically recorded by the

console.Integration with the live streaming platform Twitch will be provided in 2014; users

will be able to use voice commands to immediately begin streaming footage of their current

game directly to the service, and use the Kinect microphone for commentary and

voiceovers. Despite the ability to record gameplay, Xbox One does not

include DVR functionality for recording television programs; executive Yusuf Mehdi

indicated that Xbox One would "work in tandem" with existing TV providers, but that

Microsoft may need to work with them directly to provide extended functionality such as

DVR integration.

Games

Microsoft presented several first-party and third-party titles for Xbox One at its E3 2013

news conference, some of which are exclusive to the console. First-party titles unveiled for

Xbox One include Forza Motorsport 5, Ryse: Son of Rome, a revival of Killer

Instinct, Project Spark and a teaser for an upcoming Halo game.

Xbox One games are distributed on Blu-ray Disc and as downloads through Xbox Games

Store. All Xbox One games, whether purchased as downloads or discs, must be cached on

the console's hard drive. In the case of disc-based games, the disc will still be required to

play. However, if the game is installed on another console, and that console owner no longer

has access to the disc, the owner has the option of unlocking the install on their hard drive by

purchasing it through Xbox Live; the installed game then acts as a game installed on the hard

drive. Single-player games that take advantage of cloud computing require an internet

connection.

Xbox One does not have native backward compatibility with original Xbox or Xbox

360 games. Xbox Live director of programming Larry "Major Nelson" Hryb did state that

users could theoretically use the HDMI-in port on the console to pass an Xbox 360 through

Xbox One. In an interview, Senior director Albert Penello revealed the possibility that

Microsoft could offer backwards compatibility with older titles through a cloud

gaming system in the future.

Sales

On November 22, 2013, Microsoft confirmed that it had sold one million Xbox One consoles

within its first 24 hours of being available. Based on approximately 102,000 shopping

receipts tracked by Info Scout, 1,500 of which included a purchase of either a video game or

a video game console, the Xbox One was the highest-selling console during the Black Friday

sales period in the United States.

On December 11, 2013, Microsoft announced that it had sold approximately 2 million units

in its first 18 days on sale. On December 12, 2013, Microsoft announced it was the fastest

selling console in the United States based on NPD Group figures, however the NPD report

clarified, "PlayStation 4 sales included an additional week within the November data month

compared to Xbox One. When looking at sales on an average per-week basis, Xbox One led

PS4. Keep in mind, however, that supply typically becomes constrained in the second week

after launch."

On January 6, 2014, Microsoft announced that approximately 3 million consoles had been

sold worldwide in 2013.In their Q2 2014 earnings report on January 23, 2014, Microsoft

announced that 3.9 million Xbox One units had been shipped worldwide.

Conclusion & Future Scope:-

This research was motivated by a commercialized product of gesture-based interaction

technology, Xbox360 game console. As an advance technology, gesture-based interaction has

been applied successfully in game industry and paid more and more attention. But the

traditional interaction has existed for a long time and continued to be dominant. We collected

the data from several people by interview method and discussed advantages and disadvantage

of gesture-based interactions. It provides people new experience and great pleasure which

traditional interaction could not offer. It makes the interaction between human and computer

more natural. It has been illustrated in science fiction movies that this technology can

improve people’s lives if it is applied rightly. But there are still some disadvantages which

may bring troubles and make users dissatisfied. Hours of use make users tired soon.

Machines cannot distinguish between intentional behaviors and unintentional behaviors.

Because of the invisible boundary existed , which cannot be seen , the user is very easily

running out of the boundary, as a result, the camera fixed on the device cannot detect the

user's actions, so there is no any reactions on the system.