Disable Hyperthreading in Mac-pro 2008 from EFI?

Question

Is there a way of disabling HT at a firmware level (EFI) ?? I have a server-linux distribution and a macosx both installed in a mac-pro 2008 workstation.

Searching in google, i came up with the EFI shell command 'cpuconfig threads off' but this only seems to work on HP servers that come with EFI.

what is the solution for a mac-pro??

as an emergency solution i can disable logical CPUs in ubuntu manually one by one, but i am not sure if this is a good approach to obtain efficient performance and max cpu frequency.

Answer 1

I havent found any solution to the question in topic, but an acceptable one is to add "maxcpus=n" in the grub boot options (in my case im only using linux for hpc), in /etc/default/grub and then running "update-grub" before restart.

now i have 1 thread per core everytime i boot linux.