you might be able, I believe the mac pro uses the Standard LGA771 Xeon socket, but knowing apple, the CPU's would have to be in matched pairs, and the clock speed would have to match up with one of the possible current configurations available on that computer, and have a compatible front side bus, and the right socket. But, remember, these are Nehalem Xeons, they can out-preform an equally clocked Hex Core Opteron. they are pretty heavy duty cpu's
[quote|Chris Green]you might be able, I believe the mac pro uses the Standard LGA771 Xeon socket, but knowing apple, the CPU's would have to be in matched pairs, and the clock speed would have to match up with one of the possible current configurations available on that computer, and have a compatible front side bus, and the right socket. But, remember, these are Nehalem Xeons, they can out-preform an equally clocked Hex Core Opteron. they are pretty heavy duty cpu's[/quote]