As if the Mac Pro wasn’t fickle enough with it’s RAM needs (requiring the special heatsinks and all), the new 8 core version is even more fickle, requiring an entirely new set of part numbers for its RAM and hard drives. Thankfully the new numbers are backward compatible with the older quad core Mac Pros.
Apple kits compatible with all Mac Pro computers (quad-core and 8-core)
Part Number and description
Apple kits compatible only with quad-core Mac Pro computers
Part Number and description
Then again, I buy third party RAM and hard drives, so this wouldn’t have changed anything for me, even if I had the $4000 for one of the new machines. I like choosing the exact hard drive I want and saving money on both drives and RAM.
the larger issue here is what the differences might be, especially with hard drives. SATA 3 is pretty much SATA 3 innit?