Post on 07-Jul-2015
description
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
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
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)