Cripsy's right, everything can be overclocked one way or another. I've got a Dell Optiplex GX150 (P3 1Ghz) which after much tinkering in the BIOS I managed to crank it up to 1.3Ghz before it decided to not want to boot one day, set it back to 1.2 and it's happy. A good idea for clocking a Dell machine is to keep an eye out for BIOS updates as the early releases will often have all the options for CPU speed unlocked, whereas a few days down the road, they'll change the file to lock out the mulitpliers from prying eyes. On every recent Dell I've seen (quite a few, as my company uses them a lot) there's no jumpers on the motherboard you can change to overclock, so you have to rely on softclocking in the BIOS, but it will work. Also, if you are going to clock it, I would STRONGLY advice changing th heatsink, and as the stock HSF from Dell is pretty poor when you up the multipliers/bus speed/voltage. You have been officially warned!