Early 2008 Mac Pro CPU Upgrade

There is no processor upgrade path available by third party. Modders and overclockers risk the safety of their machine if they attempt to upgrade it themselves. There are tips on http://www.xlr8yourmac.com/ if you are that adventurous. Note any such modifications will likely result in the termination of your 1 year hardware warranty, though we can't say for certain since we don't work for Apple, and only say this based on the "unauthorized modifications" section of the warranty documentation.

Yes it is possible, but most likely not financially viable.

You will void your warranty and of the more difficult items to track down will be the heat sink for the CPU! Mind you, finding a 2.8Ghz CPU will be difficult on it's own. But in essence, if you have some cash to blow and are willing to get your hands full of thermal paste, then yes, have a go!

http://www.hardmac.com/articles/72/

and

http://www.o0o.it/pro/

Remember, on your head be it!

-Jacques

You probably will want (need) to run Windows to check on the CPU for its revision, stepping, etc as finding matched pair is the hardest part probably. And expect to pay $800+ for one.

Newegg has Harpertown Xeon, but not much if any for 1600MHz bus.

As you can see, the $500 up front wasn't really that horrible.