hi, doesn't someone happen to know some way to completely disable one of cores in windows? I need to disable it for kernel thread too. Thanks.

You mean for a multi-core processor? It would be a BIOS option. If you want to do it from an application I wouldn't know how.

I believe Windows does have such option.

anyway, thanks for idea, for now i will do it in BIOS

You can disable 1 core by setting all processes to 1 core
Its called setting a processes Affinity

I know its not exactly the same but its the only way i can think of doing it

Out of interest, why do you need to disable a core?

I don't have such option in my BIOS... You can have in view of a diasble/enable a Hyper-Threading?

f0dder: i am playing with VMX stuff, and since VMX only support virtual machines with single core, windows shouldn't expect it runs in multi-core evironment.

Oh... I dunno if there's some CRx bits you can play with for that, but I suspect it's some ACPI/whatever tables you should modify before you launch windows in the VMX? Haven't seen a BIOS that supports turning off cores, only HT.

I do have that option in my BIOS, or at least i think. It is called "Core Multi-Processing".

But problem is i will need to disable it while windows is running, so i think just disabling it in CPU registers will "confuse" windows

Hyper-Threading is not multi-core. It just gives the OS the feeling of having two CPUs for the purpose of increasing the register count and in theory increasing the processors processing power.

Vid, I'm still confused why you would need to disable one core even if VMX doesn't support both cores. Can you explain further please? There are many things I don't know and this I would like to learn.

Filter - while VMX does not preclude the use of multi-cores, it is quite difficult to manage VMs in a multi-core system. When trying to get a VMX system up and running, it's best to make your work as easy as possible. Restricting the platform to one core is a grand simplification when you're first designing, writing and debugging your beta VMX based VM. It's learning to walk before you run

Check out this paper on a VMX based rootkit. The author discusses the difficulties with multi-processors with respect to VMX. He admits he disables one of the cores in order to get his demo working (see pages 25 and 36 of his paper).