Is it a big performance gain to run a VM from a second drive?

Dell offers a laptop with either a 500GB drive or two 320GB drives (both 7200rpm and no options for SSD). I will be running VMs for development and will also have several TrueCrypt mounts.

I figure two drives are better for a): faster disk access, and b): data is on separate drive from OS. Is that right?

Solution 1:

Scott Hansellman made a blog post with great advices about VM performance. Jeff Atwood too, with some benchmarks (it's from 2006, but still useful). And all of them agree about a second hard drive for your VMs. And I agree with them. When I use VM with a virtual disk in the same disk in my Vista it's a pain.

I would follow the advices presented in these links, since they are from programmers too, so you may have similar problems.

Solution 2:

That would be a good solution. Keep the VMs on one and the OS and other stuff on the other. We found a significant improvement running the VMs on external eSATA drives for systems that did not support two drives.