Using All Cores

This may be a bit off topic for this forum. I have a macpro with 12 cores and 24 total cores including virtual cores. Running Windows 8.1. VRay is currently just seeing just “12 cores.”

Funny thing is when I was using windows 7 VRay was seeing all 24 cores.

Task Manager sees just 12 cores. It sees one of the two sockets.

Device Manager sees all 24 cores.

I contacted Chaos Group and they were unable to pinpoint the issue.

Thanks for looking!

Hi. Check to see if Windows is limiting your number of allowed CPU processors. I had this problem with Windows 7 on my i73770 which has 4 cores with 8x threads and only 4 x threads were being used and seen by Vray and Windows.
To unlock all available cores in Windows 7 (And I assume Win8) try this:
Goto the BOOT tab
Click on Advanced options button
Un-Tick the NUMBER OF PROCESSORS option.
Apply and close and reboot your system

My Windows 7 system was set to limit usable CPUs to 4, which actually means 4 x threads, not physical CPUs. With this change my Vray and Windows have been able to use all 8x threads on my system. Michael VS

Had to upgrade to Windows 8.1 “PRO”. It handles 2 cores.