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Old 2010-09-21, 18:46   #110
mdettweiler
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Quote:
Originally Posted by gd_barnes View Post
All of this begs the question of resources though. Is one GPU like one CPU core? If so, we really only have about 10-15 total GPU cores that we could throw at it at this time and I wouldn't want to monopolize Bruce's and Vaughan's GPU hours so it would be less available "cores" than that.
Short answer: yes. One GPU core behaves like a single unit.

Long answer: sometimes. Depending on the program you're running and how well optimized it is, sometimes you can actually get more throughput if you run more than one instance of it on the same GPU. However, I do not believe this is the case with ppsieve, since in my testing it is mostly GPU bound (that is, the slowest link is the GPU; not the small prime sieve portion of the algorithm which is being run on the CPU. For tpsieve, the situation is reversed and the application is CPU bound, taking almost an entire CPU core in addition to the GPU when running with properly optimized settings.)

So as far as ppsieve goes, yes, it would monopolize the GPU on which it is running.
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