by Jimmy Greystone - 3/3/12 6:13 AM
In Reply to: Question about Upgrading Early 2008 Mac Pro Memory by markw10
In general, let me just put it this way: RAM, pretty much no matter how slow, is still going to be several thousand times better than the alternative of using the HDD for swap space. So, don't get too hung up on the whole "would adding mixed density RAM modules impact performance" bit. While you might get slightly better performance if they were all the same type and density, I would focus more on maximizing the total amount of RAM installed that your budget will allow. That would be a far better long term strategy, IMO anyway.
It would also probably be a good idea to go look up the specs for that model on Apple's site, make sure it will even take 32GB of RAM. Just check the CTO options for RAM and see what that is. I wouldn't recommend trying to go over that, because the results can be unpredictable. One person might have absolutely no problem with that config while your unit refuses to even boot or doesn't recognize all the RAM, etc. I've run into that situation a couple of times in my career as an Apple repair tech.