Q: I have a Dell Dimension E521, and it has the origional motherboard, I was wanting to upgrade my processor to something that's around 3.0GHz, mine now is AMD x64 Dual Core 4000 2.1GHz. I plan on sticking with an AMD processor to avoid complications.
A: You can upgrade the CPU with the same motherboard. I'll quote from a review: "Dell offset this issue by loading up our review unit with 2GB of 533MHz DDR2 SDRAM and pairing the memory with a powerful 2.6GHz Athlon 64 X2 5000+ processor" If they did it, then it's possible. Of course, I'd consider upgrading the power supply and graphics as well... :-)