Currently, I've got a Pentium IV 2.0GHz Northwood 400FSB and the highest I can go up to is 3.06GHz Northwood 533FSB which is extremely hard to find, so I'd have to settle for a 2.8GHz Northwood 533FSB. As for the other components, they are 512MB PC800 RDRAM, GeForce4 MX420 64MB AGP (may switch to GeForce 6600GT), 200GB hard drive and a stock Dell 250W PSU at +12V/14A. I'm looking to put modern games on graphically High Settings, 1024x768, no AA/AF or very little AA.