BM Seer Unofficial thoughts from an anonymous Sun employee

Power-performance Metrics

Wednesday Mar 28, 2007

It is best to write out the equations (as reminded by Pavel).

  • Performance = operations/time (ops/sec)
  • Watt = Energy/time (Joules/sec)
  • Watt-hour= kWatt*hours = 1000 (Joules/sec) * hour, basically we are paying for a certain number of Joules.
So to derive a proper metric on the energy used per operation.
    Watt/Performance =
    =(joules/sec)/(Ops/sec)
    = joules/Op or energy per operation
    therefore
    Watt/Performance = Energy/operation
Energy is measured in kWatt*hour and that is what we pay money for.

This then is in line with our typical cost metric of $/operation. To remind everyone the industry has settled on $/performance. This is no mistake. Like it or not we live in a cost-constrained world, that is why the ratio was constructed the way it was with performance or operation in the denominator. This way one is naturally led to what is the cost per transaction, as opposed to the thought experiment if I had 'X' dollars what performance could I achieve.

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Posted at 06:00AM Mar 28, 2007 in Benchmarks
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So by this logic, Sun's own "SWaP" metric is wrong?

Posted by Xray on March 29, 2007 at 07:31 PM PDT #

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