Masking CPU Cores in Supermicro Servers

To disable a certain number of processor cores in Supermicro servers, a bitmask is used. Shutdown of cores is intended to harmonize the use of licenses for some software.

You can do this in the BIOS along the path: Advanced->CPU Configuration->CPU1 Core Disable Bitmap.

 

Masking is done in the following way. You must set the correct mask in hexadecimal format in the "Core Disable Bitmap(Hex)" field:

0 - all cores are enabled;

FFFFFFFFFFF - all cores are disabled (but in any case, one core will work on the processor).

For example, to disable a specific number of cores, let's take a processor with 26 cores and represent it in binary, where each bit corresponds to a core: 

00000000000000000000000000

Now, to disable the required number of cores, we replace the required number of zeros with ones. For example, to disable half of the 26 cores (13), we form a mask: 

00000000000001111111111111

Next, we translate the binary mask 1111111111111 into hexadecimal format and get 1FFF. Enter the number 1FFF in the "Core Disable Bitmap(Hex)" field, save the BIOS settings and reboot the server.