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iMac (Retina 5K, 27-inch, 2017 RAM Upgrade Best Practice

The base system has 2 x 4GB memory modules installed. Does it make any difference which slot the modules are in, and which modules should/must match in size? Does it make any difference whether the 4GB or 16GB are in the original slots?



iMac 27" 5K, macOS 10.14

Posted on Mar 12, 2019 10:18 AM

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Posted on Mar 12, 2019 10:28 AM

Were the original modules in slots 1 + 3? That means they are matching. And the additional modules would then go into slots 2 + 4 - which should then show exactly the way your screenshot shows - perfect. Having said all that, I don’t know that it matters that much any longer with the new arrangement of the slots.

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Question marked as Top-ranking reply

Mar 12, 2019 10:28 AM in response to James Zeman

Were the original modules in slots 1 + 3? That means they are matching. And the additional modules would then go into slots 2 + 4 - which should then show exactly the way your screenshot shows - perfect. Having said all that, I don’t know that it matters that much any longer with the new arrangement of the slots.

Mar 12, 2019 10:39 AM in response to babowa

Slots

4 -- Added 16GB

3 -- Original 4GB

2 -- Added 16GB

1 -- Original 4GB


System is running great and noticeably faster vs just having the original 8GB, so really just wondering if the system architecture would perform (even) better if I swap 1-2 and 3-4.


Also any benefit to symmetry between slot pairs (whether having all the modules being the same size would make a difference)?


I used to build PC's in the 80's and 90's... it's been a while since I've done anything to a machine with more than 1 or 2 slots total.

Thanks!


JZ

iMac (Retina 5K, 27-inch, 2017 RAM Upgrade Best Practice

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