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phobos · Mar 18, 2007, 01:51 AM

Hi to all!
I'm planning to buy the next mac pro revision (hopefully in April) but I want to make sure about the matched pairs RAM requirement.
Do I need to have all memory slots with the same amount of memory ? all slots with 1GB or all slots with 2GB and so on?
I think that this doesn't really make sense so I'm guessing that it's more of PAIRS having the same amount of ram. So the first 2 slots could be occupied by the standard 2x512MB of ram that apple sells with the machine and the next 2 slots could be occupied by 2x1GB and the next 2 by 2x512MB and so on.
Am I right by assuming that?

Also do I need to change the order of the RAM to get an increase or avoid a dicrease in speed? For example the 2x1GB in the first 2 slots and the 2x512MB in the next 2.

And finally...
Is crucial ram selling the appropriate, big heat sinks memory, that apple reccomends to avoid overheating? I remember at the first few months that there was a bit of confusion on that point.

On the hard disk side....
I'm planning to get the stock 250GB or whatever the size will be by then and install a 160GB drive I own on the second bay. What are the requirements for the hard disk? Apple states on their site that they have a SATA setup not a SATA2 setup. Is that right or am I getting something wrong? If that's right than I won't be able to use my SATA2 drive.

That's about it!!!!
Thanks in advance

chipchen · Mar 18, 2007, 04:22 AM

RAM should be matched by pairs... but can be different sizes (same within the pair though).

Doesn't matter where you have them and what order, so long as they're paired correctly.

Last... yes, SATA only, not SATA2. Just buy a 500GB SATA drive from newegg for like $150.

OreoCookie · Mar 18, 2007, 05:38 AM

SATA2 drives are theoretically fully backwards compatible. However, some older controllers have trouble with certain harddrives, then you need to switch the hd to SATA1 manually (e. g. by setting a jumper). Since the MacPro has SATA2 anyway, SATA1 and SATA2 drives will work.

(Some people will rightfully point out that SATA2 is not the same as SATA drives with a 3 GBit connection; however, for marketing people the two seem to be equivalent …)

phobos · Mar 18, 2007, 11:47 PM

Thanks for your answers people! You've been very helpful.
Has anyone bought memory from crucial for the mac pro?
If yes do the fans come on more often than usual?

Fjan11 · Apr 4, 2007, 04:18 PM

According to this page, if you match the FB-DIMMS up in quads rather than pairs you will see a 5-10% speed improvement because it allows a 256-bit adressing mode.

I wonder whether it's better to remove the original 1G if I'm adding 2x2G to a MacPro. Does the extra memory minus the extra latency that the 3rd and 4th pair generate offset the 5-10% speed increase? Anybody care to venture a guess?