RAM upgrade question.

Discussion in 'iMac' started by JoelIsaiah, Nov 27, 2012.

  1. JoelIsaiah macrumors newbie

    Nov 27, 2012
    Hey all,

    first post here. I have been enjoying reading these forum for awhile now.

    I just got a refurbished 2011 27" iMac. It came with 4gb ram (2 slots of 2gb).

    I am about to order more RAM from crucial.com.

    My question:

    What combination would I get the optimum performance from my RAM:

    Buy 2 slots of 8gb RAM to fill the two open slots for a total of 20GB RAM. OR, buy 4 4GB to fill all four RAM slots for a total of 16GB.

    Do you get better performance if you evenly distribute the ram in each slot? Or would it be fine to just add two 8GB to the two open slots?

    Thanks so much!

  2. MeFromHere macrumors 6502

    Oct 11, 2012




    You MIGHT get better performance if you install pairs of equal-size modules. It varies from system to system, and a quick scan of the above URLs didn't reveal a definite answer to me.

    Does Crucial offer any model-specific information about maximizing performance?
  3. SR20DETDOG macrumors regular

    Jan 25, 2011
    Queensland Australia
    If you're usage is exceeding the amount of RAM you have no speed increase from pairing is going to help. Even if you have plenty the difference would most likely be indiscernible, and could be made up for by simply learning how to use programs more efficiently with keyboard shortcuts etc.

    I would argue going with 2x 8GB sticks for 20GB would be the best option (this is what I'm planning to do myself) This not only gives you 4GB extra over the alternative but also easily allows you to replace the original 2x 2GB sticks with 8GBs later on for 32GB (and matched pairs).
  4. TouchMint.com macrumors 68000


    May 25, 2012
  5. CaptMike macrumors regular


    Mar 27, 2012
    If I remember correctly, the early 2012 Imac is only user upgradable to 16GB
  6. juliazo macrumors newbie

    Jun 13, 2012
    Agreed, no need to spring for 32GB right now, since, realistically, you might not need >20GB for the time being. To determine if you do, open up Activity Monitor and keep an eye on the System Memory tab while you do your normal work on the computer. Look for two things:

    1) How much free memory you have at any given time - if the "green" slice is consistently small even with 20GB, you can also try not having so many applications running...

    2) Page outs - too high a number indicates the computer keeps running out of usable RAM and needs to write data out to the HDD. More RAM will definitely help relieve that.


    The Mid-2011 27-inch iMac unofficially supports up to 32GB (4x8GB). Apple specs say 16GB max (4x4GB), but don't believe everything you read on the interwebs :D

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