S1200BTL with E3-1280v2: limit available cores - server 2008 r2 sees no hyperthreads?

[idata]

Hi,

Just have a new server with the S1200BTL motherboard and an E3-1280 V2 processor and 16GB ram.

This processor has 4 cores, which in windows with hyper-threading turned on appears as 8 processors.

But due to database licencing limitations I need to run it with only 2 cores (to use the extra 2 would need us to pay an extra $40k in licence fees!).

However, when limited to two cores in the BIOS (and with hyper threading enabled), when booted to windows server 2008 r2 sp1 enterprise edition the operating system appears to only see two processors. Normal behaviour is for task manager (and other utilities) to display the two physical cores and the two hyper threads showing four processors in total.

If I boot a linux OS then the process monitor always shows the correct number of processors counting the hyperthreads as well. So in above situation linux is showing 4 processors, not the 2 like windows.

So, I'm concerned that windows is not even using the hyper-threads available in this situation since it does not seem to know about them.

Does anyone know how I might remedy this problem?

Regards, Bryce S.

[idata · Accepted solution]

Hi,

Now solved.

Turns out 'msconfig -> boot -> advanced options' had a tick in 'number of processors' and this was set to the maximum of 2, but obviously had bad effect on the hyperthreading/core count.

Regards, Bryce.