Widely varying LL test speeds after reboot

TrellisCross · 2016-11-03, 23:42

Quick observation. I am running Prime95 v28.9 build 2, two instances of Prime95- one for each of two Xeon E-5-2960 v4 CPUs, each with 32 Gb of quad channel RAM (SuperMicro motherboard). Each CPU has 4 clients running. There are currently no other applications running except an antivirus program.

Before Windows 10 reboot:
-CPU0 workers are running at about 24 ms/iteration for a 78M exponent
-CPU1 workers are running at about 13 ms/iteration for a 78M exponent

After reboot due to Antivirus application update, all 8 workers were running at about 50 ms/iteration.

I stopped and started the workers without another reboot, but there was no change in speed (this has worked for me in the past). I then rebooted without success.

I rebooted again, and now the workers are again running at about 24 and 13 ms/iteration.

Anyone know why this might be happening? It is quite mysterious why such differences in speed exist over time.

Prime95 · 2016-11-04, 01:39

I assume each worker is using the same number of cores?
How do you make sure each prime95 instance binds it's workers to a specific CPU?
What problems did you have running one prime95 instance with 8 workers?

axn · 2016-11-04, 03:10

I don't see any E5-2960 v4 chips at ark.intel.com. The one I see is http://ark.intel.com/products/91770/...Cache-2_60-GHz. Assuming you made a typo, and it really is 2690, this is a 14 core CPU with 35MB L3 cache. Your optimal configuration will be to run 1 worker per CPU with 14 threads. And this can be easily achieved with one instance of P95 (instead of two).

sr13798 · 2016-11-14, 14:22

What is the optimal setting for a I7-6700k for one worker? I have all 4 cores assigned and I can still run other programs easily.

2016-11-03, 23:42	#1
TrellisCross Oct 2016 5 Posts	Widely varying LL test speeds after reboot Quick observation. I am running Prime95 v28.9 build 2, two instances of Prime95- one for each of two Xeon E-5-2960 v4 CPUs, each with 32 Gb of quad channel RAM (SuperMicro motherboard). Each CPU has 4 clients running. There are currently no other applications running except an antivirus program. Before Windows 10 reboot: -CPU0 workers are running at about 24 ms/iteration for a 78M exponent -CPU1 workers are running at about 13 ms/iteration for a 78M exponent After reboot due to Antivirus application update, all 8 workers were running at about 50 ms/iteration. I stopped and started the workers without another reboot, but there was no change in speed (this has worked for me in the past). I then rebooted without success. I rebooted again, and now the workers are again running at about 24 and 13 ms/iteration. Anyone know why this might be happening? It is quite mysterious why such differences in speed exist over time.

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2016-11-04, 01:39	#2
Prime95 P90 years forever! Aug 2002 Yeehaw, FL 2×4,079 Posts	I assume each worker is using the same number of cores? How do you make sure each prime95 instance binds it's workers to a specific CPU? What problems did you have running one prime95 instance with 8 workers?

2016-11-04, 03:10	#3
axn Jun 2003 5436₁₀ Posts	I don't see any E5-2960 v4 chips at ark.intel.com. The one I see is http://ark.intel.com/products/91770/...Cache-2_60-GHz. Assuming you made a typo, and it really is 2690, this is a 14 core CPU with 35MB L3 cache. Your optimal configuration will be to run 1 worker per CPU with 14 threads. And this can be easily achieved with one instance of P95 (instead of two).

2016-11-14, 14:22	#4
sr13798 Nov 2016 2·3 Posts	What is the optimal setting for a I7-6700k for one worker? I have all 4 cores assigned and I can still run other programs easily.