Processors
Processors (Intel® Core™, Intel® Xeon®, etc); processor utilities and programs (Intel® Processor Identification Utility, Intel® Extreme Tuning Utility, Intel® Easy Streaming Wizard, etc.)
12151 Discussions

Finding out disabled cores

aozcan
New Contributor I
328 Views

Hello,

 

I need to find out which cores are disabled on a CPU. How can I do this? I know that reading CAPID6 register is one of the ways, but I am not sure about how to get it done. Is there any system calls or tricks that I need to be aware of?

 

Thanks

0 Kudos
3 Replies
DeividA_Intel
Moderator
301 Views

Hello Aozcan,  

 

Thank you for posting on the Intel® communities.  

 

I am going to list, with steps, the ways that you can see the cores and threads that are working on your system:

1. Task manager.

-Task manager>performance>CPU>right click on the graph>change graph to>logical processor.

2. BIOS.

-The way to find it may be different between brands (MSI, AsRock, Asus), or if it is a laptop, try to contact the motherboard/laptop manufacturer to find the right steps.

 

Then, you can compare the information displayed with the specifications of your processor. If there is a core that is not showing or is disabled, you can try this:

-Windows key+R>msconfig>Boot tab>advanced options>check on processor> choose the disabled one>OK tap.

 

If you have any question or need further assistance, do not hesitate to let me know

 

Regards,

 

Deivid A.

Intel Customer Support Technician

 

aozcan
New Contributor I
296 Views

Hi Deivid,

 

Thanks for your reply. Is there any "C/C++" way of doing this. I want to read registers directly.  Specifically I want to read CAPID6 register into a buffer, but I am not sure if this is what I should do, and I do not how to read a register on Intel platform.

 

By the way, I should have mentioned it before: my OS is Ubuntu. I can see if a particular core is offline or online by checking  /sys/devices/system/cpu/cpu*/online to see if the file contains 0 or 1 which means offline or online respectively.

 

And also I checked link below:

 

https://community.intel.com/t5/Software-Tuning-Performance/Understanding-PCICFG-space-information/td...

 

And I understood John McCalpin's answer, but again, I am looking for a C/C++ way of doing this.

 

Thanks

DeividA_Intel
Moderator
269 Views

Hello Aozcan, 



Thanks for letting me know the operating system that you are using. The steps provided, as you noticed, are meant for Windows and since you have Ubuntu I recommend you post on our Linux community to have or get a better response based on your specifications.



You can use the following link to access the Linux community:


https://community.intel.com/t5/tag/linux/tg-p/tag-id/15



If you need any additional information, please submit a new question as this thread will no longer be monitored



Regards,



Deivid A.

Intel Customer Support Technician



Reply