An often overlooked aspect of virtualization is performance. Many times people setup a host; virtualize a couple machines and walk away. You know you are guilty of it. Maybe not all the time but it happens and we usually go back when the users complain about the performance.

As we have become more power conscious; one of the ways to conserve power was to create processors with a core parking ability which is basically consolidating production into the fewest amount of cores and then shutting down non-used cores. In many cases, this is not an issue as it centers on threaded applications. If your applications are not threaded, then you won’t gain much.  However, in the matters of virtualization, this could help with making use of cores. I observed a few of the cores at 100% while others were not in use.  After disabling cpu parking; I noticed the workload was spread out.

This is what I did to disable cpu parking on my Windows 7 VMs.

You will need regedit to disable a few keys.   There will be one for each power plan on the system so remember to use the F3 key to continue the search after you update the key.

You will want to search for the key :  0cc5b647-c1df-4637-891a-dec35c318583

Once the search presents the key, look for a value called  :   ValueMax

This is what tells they computer that all cores can be parked.

Change the value to :  0

You will need to continue searching through the registry for other instances. On average, you will only need to change two entries.

After you are finished and exit regedit, give the VM a reboot.