Anyone got any experience of using the /numproc= together with hyperthreading

Hi,

I have been trying out the numproc command in the boot.ini file and I am getting all confused.
I run a quad machine with Hyperthreading enabled, but had some problems with some of my software so needed to switch down to just use 1 physical processors.

What I am not sure about is whether the use of the command numproc automatically disables hyperthreading or not.
My thought was that to use 1 physical processor with Hyperthreading I need set /numproc=2, so it would use 2 logical processors

Well my tests seem to show that as if I select numproc=2 it seems to be that 2 physical processors gets used instead of 2 logical processors.

But I havent come up with a 100% test to prove this?
Has anyone got any ideas on how to prove whether it is the physical processors that are being used or if it is the logical processors beign used?

Cheers
Jon

 

Hi

I forgot to mention the problem I am having is a performance problem, so I want to run with Hyperthreading enabled.

Obviously setting the /numproc=1 would obviously give me 1 physical processor for sure, but how can I set it to run with 1 processor with Hyperthreading

 

Hi I am not sure if anyone is interested but I managed to find the answer. It was fairly obvious and I should have thought of it before asking. Basically Windows cant tell the difference between a physical and a logical processor, hence the beauty of hyperthreading. So when you set numproc to for example 2, then you will have 1 physical processor and 2 logical. Not 2 physical.

Cheers
Jon

 

did you notice any speed increase?