Date, location

What Network Should I Use?

Bill Menger

June 24, 2011

Outline

• Networking Options for Cluster Users

– network infrastructures

– topologies

• The Lifecycle of an innovation

• The Marketplace

• Why Ethernet?

Networks

• In the beginning… ~1999

– 100Mbit Ethernet

– Myrinet (>1Gbit/sec in 1994)

– Quadrics

• Now

– 1Ge, “channel-bonded” to 2Ge or 4Ge sometimes

– 10Ge

– Infiniband

– SeaStar (Cray routing device)

– and more…

Topologies

• torus

• ring

• kautz network (SiCortex – “n” inputs “n” outputs/device)

• hypercube

• clos (1953 – 3 layer x-bar topology)

• fat-tree (1990 – looks like a binary tree)

Topologies-Pictures

Adaptation of Innovation

Organizational Decision Making

• R&D – HPC – Scientist Decisions – Small group of specialists pick the newest, fastest, best.

(innovators - early adopters)

• Collective Innovation Decisions – The collection-innovation decision occurs when the adoption of

an innovation has been made by a consensus among the members of an organization (early majority – late majority – laggards)

• Authority Innovation Decisions – The authority-innovation decision occurs when the adoption of

an innovation has been made by very few individuals with high positions of power within an organization. (late majority-laggards)

Diffusion Curve

(what happens when an innovation wins)

10 Ge vs 1Ge Market (server shipments)

0

10

20

30

40

50

60

70

80

90

100

2009 2010 2011 2012 2013 2014

1 Ge

10 Ge

From Dell’Oro Group

Decisionmaker Thinking

Typical Winning Decisionmakers

• Late Majority

– Individuals in this category will adopt an innovation after the average member of the society. These individuals approach an innovation with a high degree of skepticism and after the majority of society has adopted the innovation

• Laggards

– Individuals in this category are the last to adopt an innovation. Unlike some of the previous categories, individuals in this category show little to no opinion leadership.

--- These are the managers in US Corporations ---

--- BUT FOR GOOD REASONS !!!!! ---

Why Pick the Ubiquitous Market Leader?

(Ethernet)

• Need Stability

• Need Guaranteed Performance

• Need Low Cost

• Need Well-Defined Software models

• Need to interface with the IT Infrastructure

• SACRIFICES MADE?

– It is not the fastest, lowest latency solution available

– It may cost more than IB in some cases (direct costs)