After searching the site for an hour, I'll just ask the question directly. What are the processors worth looking at that will swap into a first gen Mac Pro? I'm adding RAM and faster hard drives, as well as at least an ATI HD5770. Possibly even a SSD boot drive. That said, I originally bought this mac with the thought of swapping processors at some point, turning the ol' 2.66GHz quad into an octo. I know the clovertown chips will swap in, but my research hasn't moved past that. Will any Xeon that fits into a LGA 771 socket work? And if so, where are the sweet spots? Anyone who has upgraded their 2006 vintage Mac Pros feel free to post some specs or ideas as well as bench scores. Thanks!