GTX970 - Overclocking GPU
#1
This would also apply to all other GPUs.

When you overclock a GPU too much artifact begin to appear in 3D applications, but what about things like hashes?

How far can you overclock a GPU and have it still produce reliable hash mathematics?

Is there a stress test for a GPU similar to prime95 for the cpu?
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#2
Mild overclocking is totally safe as long as you keep the temps below dangerous levels (for the most part, under 90C is acceptable.) In most cases it's a bit dumb if you aren't overclocking, since that's free performance you're missing out on. Worst case scenario if you push the clocks too far, you will experience an ASIC hang and the GPU will freeze until the system is rebooted.

Yes there is a GPU stress test tool -- it's called oclHashcat Wink There's also md5stress (see the wiki.)

Edit: By the way with a GTX 970 you can probably safely do +225 - +250 clock offset.
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#3
(05-12-2015, 09:20 PM)epixoip Wrote: Mild overclocking is totally safe as long as you keep the temps below dangerous levels (for the most part, under 90C is acceptable.) In most cases it's a bit dumb if you aren't overclocking, since that's free performance you're missing out on. Worst case scenario if you push the clocks too far, you will experience an ASIC hang and the GPU will freeze until the system is rebooted.

Yes there is a GPU stress test tool -- it's called oclHashcat Wink There's also md5stress (see the wiki.)

Edit: By the way with a GTX 970 you can probably safely do +225 - +250 clock offset.

So it's safe to assume that artifacts in 3D applications (which normally indicate an unstable overclock) will not imply artifacts in hash calculations? It would not do to overclock only to have it screw up some % of hashes after all.

Does hashcat have a mode that applies stress to the GPU and also checks hash correctness? I don't think -b does that.
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#4
Usually when md5stress is discussed, I mention "MemtestG80" which tests the GPU memory and "Mfaktc" which is "A GPU based Mersenne number factoring program".

They are likely to test the circuits that also do the hash cracking.
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