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Processors

chrisclk
Adept I

GetLogicalProcessorInformationEx does not return expected values

On Windows 10, I call GetLogicalProcessorInformationEx(RelationGroup, Buffer, &Length);

The return data is that there are two groups with 32 logical processors in each group. I was expecting 64 logical processors in each group.

What are the reasons that this might be happening?

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It will be extremely helpful to know your computer specs especially the Make & Model of your CPU and Motherboard and Windows version you have installed before, at least in my case, I can give you an applicable reply.

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Its running on an AMD 3990X 64 core cpu. The system is running Windows 10, don't know the version number.

I don't have details on the motherboard etc. as I don't own the computer. I am debugging an application running on someone else's computer. I will get the motherboard/Windows version.

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Download SPECCY which will give most of your computer's hardware and software installed.

What does Windows Task Manager show under "Processor"?

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chrisclk, SPECCY is probably the worst utility you can use.  Please post the the actual output of your command.  Thanks and enjoy, John.

 

EDIT: Please run the PowerShell command get-computerinfo in an elevated command prompt and post the results.  The output will contain some personal information information, so I recommend editing before posting.  Please tell us if this is what you are looking for and if not, what is.

 

I assume you are running on the HW and not on Hyper-V?

 

Please run the utility (MS) CoreInfo from Sysinternals and post the output (check for private info)

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This website give you several ways to check your PC Hardware and software using Windows plus a couple of 3rd party APPs which they recommend which happens to contradict the other User's misinformed personal opinion: https://www.timeatlas.com/check-computer-specs/

Screenshot 2020-11-14 140516.png

 

EDIT: Found this GITHUB Thread with a similar issue as the one your having with the same processor: https://github.com/giampaolo/psutil/issues/1809

This is the processor/motherboard info:

Operating System
Windows 10 Pro 64-bit
CPU
AMD Ryzen Threadripper 3990X 44 °C
Castle Peak 7nm Technology
RAM
64.0GB Unknown @ 1064MHz (15-15-15-36)
Motherboard
ASUSTeK COMPUTER INC. ROG ZENITH II EXTREME ALPHA (sTRX4) 39 °C

The github thread seems to be about the known Windows limitation in that there are a maximum of 64 logical processors in a single group, so the 3990X 128 threads cannot be represented in a single group. The GetLogicalProcessorInformationEx call returns the two groups but does not return 64 logical processors in each group.

 

 

chrisclk, please answer my previous questions ans see this thread.  This concerns Hyper-V which does have a problem here.  That is why I asked about it.  There is a screenshot of the task manager running all 128 logical processors.  Please post the same shot of yours.  Thanks and enjoy, John.

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Thanks that should help other Users in assisting your problem.

If you don't get a satisfactory answer in this thread then try opening a AMD Service Request (Official AMD SUPPORT) from here: https://www.amd.com/en/support/contact-email-form

It may take them a couple of days to respond though.

Just for your FYI in case you hadn't seen this before in the past, Microsoft explanation of the function you are using: https://docs.microsoft.com/en-us/windows/win32/api/sysinfoapi/nf-sysinfoapi-getlogicalprocessorinfor...

Thanks for all your help with this.

I think I have discovered the issue. A 64 bit process returns 64 processors per group and a 32 bit process returns 32 processors per group. I was aware that the affinity bitmap is a problem for a 32 bit process as the bitmap is only 32 bits wide, but I thought the function could still return the number of processors. I am going to try using bcdedit to create 4 groups of 32 processors and see if a 32 bit process works properly with that.

I will take your word for your possible solution :smileyvery-happy:

I guess you are talking about this from the link I provided in my previous reply:

Screenshot 2020-11-14 140516.png

Which seems to be what you are talking about.

Hope you BCDEDIT helps finally to solve your problem.

Good luck and take care.

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