This is actually the second forum I registered to for help. I tried mac-forums, but no one had any clue. So, I got a great deal on a first generation Mac Pro. Well, most of the Mac Pro. $150 for everything but the hard drive, memory, and cpus. Which, memory and hard drives are no problem to get for the mac pro. However, CPUs on the other hand, WoodCrest and Clovertown 771 xeon core cpus work in these first generation Mac pros. But they're not so easy to find, even more at a price compared to say the Wolfdale, and Harpertown xeon cpus. Now these Mac pros using the 5000x chipset, it should have support for wolfdale and harpertown. But, also being the Mac is efi controlled, which I'm not to familiar with, would something like the EFI in the mac stop me from using Wolfdale or Harpertown cpus in the first generation mac pro?