I did try putting a Parallels VM on the SSD. It was a 20GB Windows XP VM that I use as a dev environment for some applications that run on Windows. I didn’t notice too much difference at all, and I went back to using the VM on my hard drive. It’s obviously better in some ways to keep VMs on a SSD, but I think that benefit was countered by having the VM and OSX on the same drive, maxing out the I/O.

That said, I think you would notice significant improvement putting your VMs on a SSD, separating the I/O from your OS – but that’s just my prediction.

Another option for you is an optical drive replacement available here. I may do that as well in the future since I can’t remember the last time I needed my DVD drive.

I have a Unibody 17″ (current rev), with 8 Gigs RAM, a 3.06 GHz Core 2 Duo processor, and an upgraded WD Scorpio Black 7200 RPM 320 Gig drive. So it is already as fast as you can get without an SSD.

Therefore, instead of switching the boot drive over to the SSD, I think I might first experiment with putting Parallels and all my Windows VMs on the SSD. That is the main area I would like to speed up, and I have read elsewhere it makes a big difference.

Please share your Parallels performance results if you do move them to the SSD.