Actually Parallels, like VMware, doesn't emulate the CPU, though they do emulate peripherals such as hard drives and video cards. That's why Parallels and VMware can only run guest OSes that work on the same CPU that the the virtual machine is running on. For example you can't run a 64 bit guest OS in VMware running on a 32 bit CPU host machine. VirtualPC on the other hand is actually an emulator.

What Parallels and VMware do is actually allow the guest OS to run most machine instructions directly on the CPU. Through various dirty tricks they manage to trap machine instructions which a user program would not be allowed to make, such as attempts to directly access hardware, and only emulate those instructions. The result is that much of the time, programs running in Parallels or VMware run at the same speed as if they weren't running in a virtual machine. However disk I/O and graphics output are usually slower. So while it may be true that Phoenix won't run very well under Parallels, I wouldn't assume that for sure other than lack of DirectX support.

As for DirectX support, Parallels claims to be releasing a new beta by the end of this year which supports DirectX in guest OSes, and which runs games fine. We'll see whether that's true. I'm hoping so, since I just bought Phoenix and am getting a new PowerBook Pro. I'll use Bootcamp if I have to, but I'd rather be able to run games in Parallels. If it does work, I think that will go a long way to solving the problem which prompted this thread.

Here's the page on Parallels which talks about DirectX support: http://parallelsvirtualization.blogs...are-is-in.html