Why is only 1 cpu used?

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William

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May 7, 2015
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Yup... same thing as NUMA really.
That's what I thought and reference my first comment about this.

Can you run Geekbench ?
It does see all cores/threads.

Geekbench.jpg
 
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William

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May 7, 2015
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I used to let a guy run chess benchmarks on my rigs, dual processor and the big Quad machine. He had a hard time at first as all the current chess programs at the time were not NUMA aware. The programmers had to go back and fix code to be able to use all cores in these systems. Took then a while but they finally got it.
 

wildpig1234

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Aug 22, 2016
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geekbench ran fine. uses all threads for the most part. except it seems like one of the tests only use one processor group....

Yep, this is definitely going to be a problem. I don't know whether to blame MS for this limit or the app writers for not making sure their apps can use more than one processor group.

At least I have my answer now. too bad the solution does not come easy for everything.
 

William

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May 7, 2015
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I have a feeling its something like this... The Chess programmers just didn't have access to multi processor systems. Even Tamas from AIDA64 doesn't, I have been a help to him also.

Its also one of the reasons I do not run PCMark 10 on my reviews, dual processor systems scores just suck badly, prolly for the same reason as above.
 

wildpig1234

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Aug 22, 2016
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well, given that we are seeing more and more cores everyday, what used to be "more than adequate" at 64 logical cores is no longer true, given the latest xeon and epyc. I don't know if MS will be able to do a workaround regarding this processor group limited to 64 logical cores for the next windows update. I am thinking they won't be able to.

So that leaves it to programmers to make sure that their programs are enable to use more than one processor groups..
 

n-type

New Member
Jan 21, 2017
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I have a feeling its something like this... The Chess programmers just didn't have access to multi processor systems. Even Tamas from AIDA64 doesn't, I have been a help to him also.
If it's any help the BCD has options to make processor groups on single socket systems. It's not ideal and a little buggy but does have it's uses when not having access to a multi socket system.

Single 2683v3, running on group 1 with 12 threads


Note that distribution isn't always even. Also things can get a little funky with OSes that only support one socket such as "Home" so might be better of with "Pro" or equivalent or perhaps a server version.

For CPU-Z bench I would recommend bringing it up with Franck at CPUID. If you can discus in French then even better. BTW I don't think CBR11.5 supports groups either. So many softwares not able to take advantage...
 
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wildpig1234

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Aug 22, 2016
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If it's any help the BCD has options to make processor groups on single socket systems. It's not ideal and a little buggy but does have it's uses when not having access to a multi socket system.

Single 2683v3, running on group 1 with 12 threads
Note that distribution isn't always even. Also things can get a little funky with OSes that only support one socket such as "Home" so might be better of with "Pro" or equivalent or perhaps a server version.

For CPU-Z bench I would recommend bringing it up with Franck at CPUID. If you can discus in French then even better. BTW I don't think CBR11.5 supports groups either. So many softwares not able to take advantage...
how do i use bcd to set processor group? maybe what i could do is set a group with max number of logical cores of 64 and hopefully cpuz will use that group. still not ideal...

i have no idea how to contact franck. the email and suggestion form on cpuz website has some sort of error that ask you to fill in the capcha but there is no capcha displayed. i 've tried it with like 3 different browsers.
 

wildpig1234

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Aug 22, 2016
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I was thinking also. is there anything a program could do to truly benchmark 1 cpu only in a machine with dual cpu? like for instance, I ran cinebench with just one 2686 v3 in the MB and got a cinebench score of 1988. in dual cpu, it's 3780. but I am just wondering if it's possible for a benchmark program to do something like that or does the presence of a 2nd cpu makes that impossible? it's good a lot of time to know this and I think cinebench should have this feature if possible truly bench only 1 cpu in a machine with dual cpu since this single cpu bench would help a lot of people only running single cpu socket boards.
 

cactus

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Jan 25, 2011
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I was thinking also. is there anything a program could do to truly benchmark 1 cpu only in a machine with dual cpu? like for instance, I ran cinebench with just one 2686 v3 in the MB and got a cinebench score of 1988. in dual cpu, it's 3780. but I am just wondering if it's possible for a benchmark program to do something like that or does the presence of a 2nd cpu makes that impossible? it's good a lot of time to know this and I think cinebench should have this feature if possible truly bench only 1 cpu in a machine with dual cpu since this single cpu bench would help a lot of people only running single cpu socket boards.
In win7 you could set the affinity of the process and it should stick to one CPU (or any number of cores you want). IIRC, win10 ignores the affinity set through task manager and you need to make a batch script or shortcut to do it.
 

wildpig1234

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Aug 22, 2016
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In win7 you could set the affinity of the process and it should stick to one CPU (or any number of cores you want). IIRC, win10 ignores the affinity set through task manager and you need to make a batch script or shortcut to do it.
but will that truly give a correct benchmark of running only a single cpu or would that just half the cinebench of a dual cpu system?

for example, I got cinebench score of 1988 when I only have one cpu in the mb. when I have two cpu the score was 3780. so if I do the processor affinity for one cpu, would I get around 1988 or would I get half of 3780?
 

manfri

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Nov 19, 2015
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Maybe a short term solution can be limit in bios (some server platform can do it) so thath the system see only 64 cpu, that, maybe, can permit a not processor group aware software to use (in your case) 64 cpu instead of 36.
 

wildpig1234

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Aug 22, 2016
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Maybe a short term solution can be limit in bios (some server platform can do it) so thath the system see only 64 cpu, that, maybe, can permit a not processor group aware software to use (in your case) 64 cpu instead of 36.
don't think anyone would make a bios setting for that. that just promote lazy software writing.
 

Syr

Member
Sep 10, 2017
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The process group extender is actually a really nice find. Granted, almost everything I use is process-group aware in this day and age, but its nice to have for the handful of programs that aren't, and im sure its a bigger issue for some other people who are stuck on software that isnt aware.