Tabor Research has reported the results for its first 'Quick Question' web poll.  The Quick Question series is designed to survey the HPC community on a variety of topics. Interested individuals register their vote via the Tabor Research website at www.taborresearch.com.

The first question posed was:

• How important is power consumption in comparing competing technologies?

Users could select one of five choices:

• Low power consumption is an absolute requirement
• Not an absolute requirement, but worth paying a premium for
• Not worth paying a premium for, but an important consideration when price/performance is equal
• Minor consideration at best
• Not important at all 

Not surprisingly, respondents reported that power consumption was an important factor in HPC computer system evaluation and selection. What was surprising was the extent of the landslide victory for power concerns. More than a third of respondents indicated that “Low power consumption is an absolute requirement.” This was the leading vote getter. In addition, close to 30 percent of respondents indicated that low power consumption was worth paying a premium for.

As surprising as the high number of respondents concerned about power was the low number — less than 5 percent – who indicated that power was a minor or non-concern. We had expected higher numbers in this case based on a Somebody Else's Budget effect, where electrical costs were covered by overhead or higher organizational budgets and thus not a concern to the respondent. (This is similar to the “somebody else's problem field” described in The Hitchhikers Guide to the Galaxy, and used to render objects invisible.) Today on earth, it seems, power consumption has become everybody's problem.

Finally, about a third of the respondents were in the moderate voter category, indicating that low power was not worth paying a premium for, but an important consideration when price/performance is equal.

For more information about the Quick Question methodology and to see the complete results, go to http://www.taborresearch.com/premium/article/1536790.html (registration required).

Tabor Research Analysis: The Dark Side of Scalability

Since the turn of the century, the HPC community has relied on a scalability strategy to address its computational requirements. This strategy leverages the price and absolute performance growth curves of computers based on commodity components. HPC users have grown capacity by “racking and stacking” larger numbers of computational nodes into cluster configurations. At the same time system providers have packed more power into each node by increasing the number of processor sockets in a node, and the number of cores in a processor. Over the last two to three years, users have begun to experience “diseconomies of scaling” to a growing degree. In contrast to performance there are aspects of computer systems that scale with system size, but which have negative effects on cost and productivity. These include:

• Power costs – Power requirements scale with both number of nodes and capability of nodes (speed of processor, on-node disk, amount of memory, etc).
• Cooling costs - The second law of thermodynamics strikes again. Computer operations produce heat as a byproduct, and systems fail if they overheat. Thus cooling requirements scale with power requirements.
• Space costs - Floor space requirements scale with number of nodes. This problem is mitigated somewhat by the introduction of more powerful nodes, but confounded by requirements to get power cables in and heat out.
• Complexity - As the number of nodes, processors, and cores increases, so does the effort required to manage and program the systems. As complexity scales up with system size, efficiency and productivity scale down, leading to lower or negative returns on investment. This issue is becoming the central challenge for the HPC industry.

None of these issues is new to the HPC world; however, we believe that the results of this quick survey are indicative of their increasing importance. Users have scaled their systems to the point where power issues have become a major concern and could inhibit the growth of installations. We believe that if the Quick Question had been based on any of the other three diseconomy factors, the results of the poll would have been virtually the same.

Future Quick Questions

A new Quick Question poll is currently active at www.taborresearch.com. It is targeted at users and asks “Which of the following CPU architectures are you most likely to select for your next purchase?”

Comments on this question and suggestions for future questions are welcome. Please contact either Chris Willard ([email protected]) or Addison Snell ([email protected]).

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Source: Tabor Research