Almighty,
It's hard for me to put a number on things. I know that Win2K slows down but I'm almost positive it has to do with RAM - there's quite a lot of disk thrashing when I switch between using Win2K and the VMWare software. And I've got 256MB RAM. I've only done light things on Win2K while a VM was running, like web browsing. It was just as fast, it just took a while for things to get started because of the disk thrashing. So I'd say the bottleneck for performance lies with the RAM first. Since the VM is just another process as far as Win2k goes, you could probably change it's priority to either give it more CPU time than other programs running under win2k, or make it share CPU time nicely. The only number that I've really looked at is CPU useage when playing an MP3. In win2k using winamp, the CPU useage according to task manager is ~3% on my Celeron 520. Using XMMS on Slackware 7.1 in a VM, the CPU useage is 15%. Quite a big jump. But I've never had an mp3 skip while using the VM even while doing intense things
-GL