Memory options for iMac

Question

Memory options for iMac

Does the Late 2013 iMac with 3.5 GHz i7 support triple or quad channel memory? I am running Mavericks 10.9.5 with the stock 8GB and trying to find the highest possible memory bandwidth the machine can run.

In other words, will 2x8GB, 3x4GB, or 4x4GB will give the highest speed access to memory? I am not often seeing the used RAM exceed 7GB, so I am not too worried about passing 12GB if triple channel is supported.

iMac, OS X Mavericks (10.9.5)

Posted on Sep 25, 2014 2:35 PM

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Answer 1

rkaufmann87

Level 10

140,664 points

Sep 25, 2014 3:56 PM in response to BrianAdam3342

BrianAdam3342,

The answer is really pretty simple, iMacs are fussy about upgraded RAM installed. If you want your machine to work reliably follow these three rules of thumb and you will likely be rewarded with years trouble free RAM use. :

Buy high quality RAM from recommended sources such as OWC (www.macsales.com) or Crucial
Stick with the specifications Apple recommends.
Install matched sets of RAM. If you are going to continue using your existing 8GB,
- add 2x4GB = 12 GB
- add 2x8GB = 24 GB or if you want to max out at 32GB
- add 4x8GB = 32 GB

Add the RAM in options 1 & 2 to the 2 empty slots when you open the iMac's RAM door.

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Answer 2

den.thed

Level 9

77,236 points

Sep 25, 2014 4:28 PM in response to BrianAdam3342

To add to rkaufmann87 spot on advise.

Only the 27" model has an external access cover for upgrading the RAM. The 21.5" model is a sealed unit and requires disassembling to upgrade the RAM.

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