Why does a GPU uses more FLOPS then a CPU, for the same job?


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Questions and Answers : GPU applications : Why does a GPU uses more FLOPS then a CPU, for the same job?

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Profile Fred J. Verster
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Message 979987 - Posted: 17 Mar 2010, 15:19:18 UTC

Looking at some fresh result's, I noticed, all WU's crunched by a CUDA device, display more(~5%-10%?) FLOPS, compaired with a CPU, on the same WU.

F.i.this one , and this
one, crunched by a
CPU!
But also stock, compaired to optimized CUDA
Can anyone please (try to) explain, this, IMO strange
fact.

Or has this to do with parallel (pre-)processing?
Since this CUDA proc. is much faster, 2x -50x, then CPU proc. a 10% increase in FLOPS, can be ignored,IMO.

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Message 984636 - Posted: 28 Mar 2010, 1:14:58 UTC

I believe the reason behind it is the CPU can do some calculations in a single calculation which the GPU has to do in a couple.

It would be like asking the CPU to do 2x2 it would figure it out with one calculation of 2x2=4 where as the GPU would have to 2x2= 2 groups of 2 means 2+2=4 (2 calculations)
That's obviously not a true case but I'm sure you get the idea.

Bob
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Profile Fred J. Verster
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Message 988881 - Posted: 13 Apr 2010, 12:36:40 UTC - in response to Message 984636.

First, sorry for my very late reply, as the question itself was a bit stupid.

The GPU will work as a kind of secondary processor, together or after some (pre)calculations, have been done by the CPU, IMO.


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Message 991271 - Posted: 23 Apr 2010, 2:15:41 UTC - in response to Message 988881.

i forgot but their was a dam good article about this. if i remember link i will post it or pm you.
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Questions and Answers : GPU applications : Why does a GPU uses more FLOPS then a CPU, for the same job?

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