Is the processor user upgradable? I have been without a desktop since my G4 Quicksilver died and am ready to get a new one. I don't want the quad because I want the ability to upgrade the memory beyond 8 gb, but don't want to shell out $5000.00 for the 2.93 Ghz version, I plan on getting the 2.26 octo and upgrading the processor down the road if needed. Any thought?