Memory upgrade for 2 x 2.8 GHz Quad-Core Intel Xeon MacPro

I recommend OWC. Go here and click on the appropriate model.

There are other vendors of course but OWC is always reliable. Ramseeker is a pretty good place to compare prices.

you should and suppose to run 800MHz, so yours run 4% slower according to barefeats.

http://www.macsales.com/memory/macpro

DDR3 you are looking at is for 2009 and later, not yours, not DDR2 FBDIMM you want.

Crucial and Amazon or Kingston and dozen others, but make sure it is certified "Mac Pro" and 800MHz.

If you have the slots and place them in the proper groupings, no. See the notes on the OWC page for what can be mixed and matched (* and ** light gray items).

yes, you're right, and I'd be inclined to go with OWC. just remember two things-

they have to be FB-DIMMS and they have to be in same pairs (mix n' match just doesn't work), and there is an order as to how the ram goes in, too....

so much to remember, eh?

John B

I get it now. I need 800MHz DDR2. Is that right?

Here's what I believe is the proper diagram to help you understand where the dimm pairs go.

Adding a question to this post. When I got my Mac Pro (2x2.8 quad core Xeon) from apple, it had two DIMMs, each 1GB. They were in position 1 in Riser A and Riser B. This diagram would suggest that that was not the proper set up ... they should have been been on Riser A, positions 1&2. Am i looking at this correctly? Did apple set mine up incorrectly at the factory?

Exactly what model year mac pro do you have? You said 2.8 GHz Quad-Core". Which year is that? I wasn't sure and I took that diagram from a pre 2008 mac pro service manual. Below is the one from the "early 2008" mac pro service manual and this appears to agree with what you are seeing.

I have an early 2008. Thanks so much for taking the time to post this. It all makes sense now. Thanks again!!!