Prime95 and cpu affinity

pepi37 · 2019-04-22, 08:23

I have two computer , with Win 7 and Win10 , both have same CPU i5-4670K
Also have two GPU , Nvidia 1050Ti and Rx580 .
My question ( I cannot solve this problem)
If I put that GPU execute and running GFN sieveless program, it use 25-30% of CPU ( so little more above one cpu core- those CPU doesnot have HT)
So when I start Prime95 and tell them to one worker use three remain cores it only use one core.
In same time, and with same scenario LLR use 3 core without any problem.
Does someone have solution for this?
I try to change affinity of cores, but that doesnot help.

Prime95 · 2019-04-24, 18:24

Prime95 should not do that -- I believe it should tell the OS to run the 3 threads on any core. When starting prime95 does it tell you which logical CPUs it is assigning threads to?

You can try setting "Affinity=1,2,3" in the [Worker #1] section of local.txt. That might help.

If still having trouble, run a benchmark (abort it anytime) and send me the hwloc topology written to either results.txt or results.bench.txt. Also send prime.txt and local.txt.

Good luck

pepi37 · 2019-04-24, 19:28

here it is

https://www.dropbox.com/s/ha9lhi4f90...ime95.zip?dl=0

Your suggestion didnot solve problem

Prime95 · 2019-04-25, 04:11

I tried to replicate the problem on my quad core Win10 machine but I was not successful.

This won't help but will provide me some extra assurance that prime95 is calling hwloc's set_affinity routine properly. In prime.txt set AffinityVerbosity=2 and restart. As before, post the picture of prime95 starting up.

One other user reported a nearly identical problem several months ago (or is this your second bug report?). At this point, I'm stumped.

pepi37 · 2019-04-25, 05:51

Quote:

Originally Posted by Prime95

I tried to replicate the problem on my quad core Win10 machine but I was not successful.

This won't help but will provide me some extra assurance that prime95 is calling hwloc's set_affinity routine properly. In prime.txt set AffinityVerbosity=2 and restart. As before, post the picture of prime95 starting up.

One other user reported a nearly identical problem several months ago (or is this your second bug report?). At this point, I'm stumped.

Quote:

[Apr 25 07:49:48] Worker starting
[Apr 25 07:49:48] Setting affinity to run worker on logical CPUs 1 (zero-based)
[Apr 25 07:49:48] Affinity set to cpuset 0x00000002
[Apr 25 07:49:48] Setting affinity to run helper thread 1 on logical CPUs 2 (zero-based)
[Apr 25 07:49:48] Affinity set to cpuset 0x00000004
[Apr 25 07:49:48] Setting affinity to run helper thread 2 on logical CPUs 3 (zero-based)
[Apr 25 07:49:48] Affinity set to cpuset 0x00000008
[Apr 25 07:50:03] Resuming PRP test of 95*10^1593538-1 using FMA3 FFT length 384K, Pass1=384, Pass2=1K, clm=4, 3 threads
[Apr 25 07:50:03] Iteration: 2326703 / 5293625 [43.95%].

As you say it doesnot help but seems Prime95 cal hwloc's set_affinity routine properly

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2019-04-22, 08:23	#1
pepi37 Dec 2011 After milion nines:) 2·3²·7·13 Posts	Prime95 and cpu affinity I have two computer , with Win 7 and Win10 , both have same CPU i5-4670K Also have two GPU , Nvidia 1050Ti and Rx580 . My question ( I cannot solve this problem) If I put that GPU execute and running GFN sieveless program, it use 25-30% of CPU ( so little more above one cpu core- those CPU doesnot have HT) So when I start Prime95 and tell them to one worker use three remain cores it only use one core. In same time, and with same scenario LLR use 3 core without any problem. Does someone have solution for this? I try to change affinity of cores, but that doesnot help.

2019-04-24, 18:24	#2
Prime95 P90 years forever! Aug 2002 Yeehaw, FL 2·4,099 Posts	Prime95 should not do that -- I believe it should tell the OS to run the 3 threads on any core. When starting prime95 does it tell you which logical CPUs it is assigning threads to? You can try setting "Affinity=1,2,3" in the [Worker #1] section of local.txt. That might help. If still having trouble, run a benchmark (abort it anytime) and send me the hwloc topology written to either results.txt or results.bench.txt. Also send prime.txt and local.txt. Good luck

2019-04-24, 19:28	#3
pepi37 Dec 2011 After milion nines:) 3146₈ Posts	here it is https://www.dropbox.com/s/ha9lhi4f90...ime95.zip?dl=0 Your suggestion didnot solve problem

2019-04-25, 04:11	#4
Prime95 P90 years forever! Aug 2002 Yeehaw, FL 2·4,099 Posts	I tried to replicate the problem on my quad core Win10 machine but I was not successful. This won't help but will provide me some extra assurance that prime95 is calling hwloc's set_affinity routine properly. In prime.txt set AffinityVerbosity=2 and restart. As before, post the picture of prime95 starting up. One other user reported a nearly identical problem several months ago (or is this your second bug report?). At this point, I'm stumped.