How to fix 8 core processor only registering one core

If your 8-core processor is only registering one core, it may be due to the configuration of processor groups in Windows. Here are a few steps you can take to troubleshoot and potentially resolve the issue:

1. Check Processor Group Settings: Windows may limit the number of logical processors available to a single process. The %NUMBER_OF_PROCESSORS% environment variable can reflect only the processors in the assigned processor group. If your system has more than 64 logical processors, ensure that your applications are set to use multiple groups.
2. Use BCDEdit to Adjust Processor Group Settings: You can maximize the number of processor groups by using the BCDEdit command. Open an elevated Command Prompt and run:

      bcdedit.exe /set maxgroup on
   

   After running this command, restart your computer to apply the changes.
3. Reset the Groupsize Setting: If you have previously set the groupsize option, it might limit the number of processors. To reset it to the default setting of 64 logical processors per group, use the following command:

      bcdedit.exe /deletevalue groupsize
   

   Again, restart your system after this change.
4. Check BIOS Settings: Since you've already reset your BIOS settings to default, ensure that any settings related to CPU configuration are enabled, particularly those related to multi-core support.
5. Update Drivers: Ensure that your chipset and processor drivers are up to date, as outdated drivers can sometimes cause issues with processor recognition.

If these steps do not resolve the issue, further investigation into hardware compatibility or potential BIOS updates may be necessary.

References:

• The %NUMBER_OF_PROCESSORS% environment variable may show incorrect values
• Boot Parameters to Test Drivers for Multiple Processor Group Support

Please type cmd in the search on the taskbar. Don't press enter key yet. Instead, choose "run as administrator" to launch Command Prompt.

Then run this command:

wmic cpu get NumberOfCores,NumberOfLogicalProcessors

How many does it return?

If it still shows 1, please run the following command while you are still in cmd admin mode, and share a screenshot of the content returned:

bcdedit /enum