If I were to upgrade: http://www.apple.com , and go for the high-end (ab't $2500-$3000 or so, not counting the monitor). I'd do it because 1) I'm lazy, 2) OSX kicks arse in the 64-bit department, and 3) I don't have to futz around w/ anti-virus, spyware, or any other resource-sucking apps. PC-only stuff? Prolly the following: * a motherboard that can support everything below... * dual Core2Duo - a single quad core will mean four cores fighting for the same front-side bus, IIRC. Only problem is, Windows kinda sucks hind teat in the 64-bit department for now. They'll get the problems ironed out eventually, though, so 64-bit ain't a bad idea. * DDR2 RAM - the faster, the better. And tons of it, preferably 2-4GB. * Dual SATA2 hard drives, hardware RAID-0 striped. 500MB each will do, but you may want to shoot for a pair of 750's. The big thing is spindle speeds... the faster, the better. Same with hard drive Cache. Skip the 8MB, and go for 16 or 32MB if you can swing it. * video cards - a later-model NVIDIA GeForce works well enough... you won't reap much benefit from SLI or anything just yet - give it a couple of years through and it'll prolly become standard. Other than that, you should be set. HTH, /P