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Old 2010-12-12, 05:48   #12
ixfd64
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"Danny"
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Looking back at this thread, I have a suggestion: it would be useful if Prime95 had a feature that automatically detects (or tries to) the optimal CPU affinity setting.
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Old 2010-12-15, 19:09   #13
ixfd64
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Hmm, Prime95 still slows down from time to time, sometimes down to 500 seconds between screen outputs for P-1 (like when I disabled hyper-threading); the only difference is that it doesn't happen as often as it originally did.

Does anyone know if version 26.x is better at handling hyper-threaded CPUs?
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Old 2010-12-18, 06:56   #14
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On second thought, I don't think the "slowdown" is related to the hyper-threading at all. According to the official specs, the i7-720QM normally operates at 1.6 GHz, with a 2.8 GHz Turbo Boost. For the record, 2.8 / 1.6 = 1.75.

As I mentioned earlier, the time per 500 P-1 iterations was fluctuating between 65 and 115 seconds. 115 / 65 = 1.77, which is very similar to the ratio for the CPU clock speeds. So the "issue" was most likely the result of the CPU operating at its normal speed. That having been said, does anyone know of any good ways to maximize the use of Turbo Boost?

By the way, Prime95 will still occasionally slow down by an order of magnitude, but restarting the computer usually solves this problem.

Last fiddled with by ixfd64 on 2010-12-18 at 06:56
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