How to ensure reliable performance data from VM's when using multiple virtual CPU's.

If you're running Windows Server 2003 in a Hyper-V VM and have the VM configured to use multiple virtual CPU's you may have noticed that performance counters seem to be reporting odd results. To work around this you may need to run bootcfg and set the /usepmtimer switch.

More information on this and other reasons why you might want to set the /usepmtimer switch can be found over at Tony Voellm's blog.