I want a fast OS drive, and there's no option for the WD Raptor.
A pair of WD Raptors in RAID0?
I meant that there's no option for the raptor drive in the Dell machine.
Yeah, I know -- I was a bit quick off the mark.
What I meant was: if you want a fast OS disk, you could get Dell to put a pair of disks in and run them in RAID0. If you're building your own, put a pair of raptors in RAID0 configuration. If I could afford it, and if I used my desktop PC as much as I used to, this is what I'd do. To be honest, I might save up and rebuild it like with a pair of Raptors when I rebuild it with Win7 RTM.
While, personally, I build my own PCs (because it's slightly cheaper, you get the bits you want and it's fun), for most people, I just recommend that they get something from Dell.