installing memory

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Level 1

5 points

installing memory

I want to install more memory into my Mac Pro - 2.8 GHz Quad-Core Intel Xeon - mid 2010 model.

I have 3 - 1 GB dimms in slots 1, 2 and 3. I want to buy a 4 GB dimm for slot 4. Will this work?

I talked with Apple tech support and they assured me that it would. Just checking to see if anyone else has done this and has it worked.

Thanks!

Mac Pro, Quad-Core Intel Xeon, Mac OS X (10.6.8)

Posted on Jul 24, 2012 5:23 PM

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Answer 1

RatVega™

Level 4

2,005 points

Jul 24, 2012 7:06 PM in response to Wendy Byle

It will work, but the performance may not be as good as using matched sets of RAM.

I'm honestly not sure how the newer processors are at handling asymetrical memory arrays, but "good practice" has always been to work in pairs, as in: Keep two 1GB dimms and add a pair of 2GB or 4GB dimms. or, just add one more 1GB dimm.

But it's your circus, you can have as many clowns as you like...

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Answer 2

Jul 24, 2012 7:44 PM in response to RatVega™

"Matched pairs" is optimum for 2008 and earlier.

In 2009 and later, optimum is (any size) triples.

The penalty for installing two or four is small, probably about five percent in memory testing. The real-world penalty for that mis-match is probably negligible.

Slots 3 and 4 are "shared". Install the big one in slot 1 (or 2) but not 3 or 4 or the memory wizard will yell at you, and tell you to change it.

Some 4GB and larger DIMMs do not play nice with other, smaller DIMMs.

So be certain to buy from a Mac-centric vendor who can tell YOU what will work in your Mac, guaranteed or your money back. Lifetime replacement warranty is the standard. Don't settle for less or you may end up owning some excellent DIMMs that do not happen to work in your Mac.

Your Mac Pro (65 lb. tower) uses Error-Correcting-Code (ECC) memory. Installing non-ECC memory is not a good way to save money in the long run.

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