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Old 2012-08-24, 14:04   #4
ldesnogu
 
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Jan 2008
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Quote:
Originally Posted by fivemack View Post
http://www.phoronix.com/scan.php?pag..._cluster&num=4 does something similar; running an embarrassingly parallel benchmark over 12 cores on six pandaboards, he gets 53 Mops at 30.4 watts. In http://www.phoronix.com/scan.php?pag...cluster&num=11 he runs a slightly different benchmark on four threads of one i7/3770K and gets 277 Mops at 107 watts.
The problem with that setup is that the ARM cluster is made of 6 full boards. That setup is said to idle at 15-16W and observed peak power is 31W.

For the example you give, let's say idle is 15W, so that'd give about 16W of power consumption, for 55.2 Mop/s. So 3.45 Mop/s/W.

The Ivy Bridge system is idling at 41W and 107W on the benchmark. So 277.9 Mop/s for 66W. So 4.21 Mop/s/W.

Of course, this assumes that idling is really idling on both platforms

Anyway I think that for many FP intensive tasks IVB would be more power efficient. Perhaps with ARMv8 and proper FP SIMD support will things change.
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