A friend is upgrading a 2007 Mac Mini with 1GB of RAM.

This model can support up to 4GB or RAM installed, but will only use a maximum of 3GB. So, his options are to install 2 x 1GB, 2 x 2GB, or 1 x 1GB + 1 x 2GB DIMMS.

I see notes saying matched memory is faster. It's hard for me to believe that having 2GB matched would be better that 3GB when running Lion. But does 2 x 2GB count as "matched" in this case? Has anyone ever actually tested?

  • Pairing gives you about an additional ~3-5% performance increase (depending on what benchmarks you look at). But at the end of the day, your decision will probably be motivated by cost. Two sticks of 2GB will likely be cheaper than (or infinitesimally more) 2x1GB sticks or one stick of 1GB and one stick of 2GB. I would advise you pick up 4GB, whether or not you can only use 3GB is moot and still a better option than a pair of mismatched 1 and 2GB sticks or a paired total of 2GB. – user10355 Jan 5 '12 at 22:35

The difference in speed between matched/unmatched pairs will be completely negligible vs having more RAM.

Tell your friend to get as much as he can. 3 > 2 always :)

I haven't tested that particular case, but I have played with a Mac Pro (that offers eight memory slots) and although I have them in the "best possible scenario", when I didn't (for a while I was testing a different "less optimal" setup), I couldn't really notice the difference…

I recommend you head over to Crucial and fill the fields to find the type of memory you can install. They have a decent model/type database and tips to obtain the best combination.

But again, I recommend > memory rather than worrying about memory performance. More is better :)

  • macsales.com sez: "Based on the results from our series of real-world application testing, it has since been our recommendation that having more memory installed via a non-matched pair provides better system performance than a lesser amount of memory attained from an installed pair. Simply put – the more total memory, however configured, the better." – radarbob Apr 10 '12 at 2:37
  • @radarbob that's exactly what I said :) – Martin Marconcini Apr 10 '12 at 12:59

Go for 2GB + 1GB or even just buy one additional 2GB stick and call it a deal for the whole amount of 2.5GB.

In case you wonder what dual channel will give you look at this table.

And regarding your main question it does seem that 945GM chipset used will run 2x2GB in dual channel despite being able to adress only three GBs.

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .