Disable CPU Core Parking

One of the new features of Windows Server 2008 R2 and Windows 7 is the ability to park one or more CPU’s cores if the machine does not need all the CPU resources.  The primary purpose of this is to save power.  However for performance reasons, one may want to ensure all CPU cores are operational all the time.  Further discussion about this feature is found here: http://thelazyadmin.com/blogs/thelazyadmin/archive/2009/02/05/what-s-new-in-2008-r2-core-parking.aspx.

This is the case for my team.  For performance purposes, we needed to ensure that all our servers cores were running.  After looking around, the following are the steps we found to disable the CPU core parking feature of our server.

1. Run the Registry Editor.
2. Search for this key: 0cc5b647-c1df-4637-891a-dec35c318583.
3. Look for the value called ValueMax. This shows the percent number of cores that will be parked.  The default is 100%, which means all cores are candidates to be parked.  Change the value from 64 to 0 (zero) so both the ValueMin and ValueMax values are zero.
4. Search the Registry for other instances of the key and repeat the process of changing the value of ValueMax each time it is found. The number of instances the key will be found will depend on the number of power profiles in the system.
5. Shutdown the computer and do a cold-re-start.

To see how this is done in action, check out this video from The PCMichiana Tech Help Show: http://pcmichiana.com/disable-cpu-core-parking-for-multi-core-processors-faster-7-episode-20/.

Hope this helps. Enjoy. 😀