Currently I’m involved in a private cloud project. In this project we really using beast of machines. We’re using HP DL980 servers. These servers have 1TB of memory and 8 – 10 Core CPUs. So we have 80 CPU cores available and with hyperthreading enabled 160 logical processors.

We are using Hyper-V Server 2012 as the host OS. After the installation was finished I looked at the Task Manager because I was curious if we had enoug CPU power Knipogende emoticon. However when I opened the Task Manager and switched to the Performance tab I see a strange number of CPU’s. Only 64 Host logical processors are shown in Task Manager:

Screenshot

The supported Number of logical processors on a Hyper-V Server 2012 host is 320 so this can not be the problem. The maximum virtual CPUs supported in a virtual machine is 64. Now we all know that the parent partition is also a virtual machine but in previous versions of Hyper-V server we allways see the correct number of host logical processors even if this was more than four (this was the support number of vCPUs in a vm in Hyper-V Server 2008 R2). ..

My question now is this a cosmetic bug in Windows Server 2012? If anyone knows the answer, please let me know!

To be continued….

Only one minute after posting this blog my fellow Hans Vredevoort pointed me to: http://www.windowsitpro.com/article/hyper-v-server/windows-2012-64-logical-processors-144278

So no bug but default behavior, thanks Hans!