3 Replies Latest reply: Jan 12, 2013 12:22 AM by yackem
natancaleb Level 1 (115 points)

HI, i just order the new 27" iMac. I do a lot of video editing and upgraded to

the following configuration:


3.4GHz Quad-core Intel Core i7, Turbo Boost up to 3.9GHz


8GB 1600MHz DDR3 SDRAM - 2x4GB


3TB Fusion Drive




I  didn't want to pay the extra 500 bones for the 32 g of Ram through he apple store. I'm wondering if there is a specific type or brand of  32GB 1600MHz DDR3 SDRAM - 4x8GB that i should order. or if 32 is over kill?



iMac, OS X Mountain Lion (10.8.2)
  • Kappy Level 10 (265,900 points)

    I would examine the info in Activity Monitor when you are working to see if you need more memory.


    About OS X Memory Management and Usage


    Using Activity Monitor to read System Memory & determine how much RAM is used

    Memory Management in Mac OS X

    Performance Guidelines- Memory Management in Mac OS X

    A detailed look at memory usage in OS X


    Understanding top output in the Terminal


    The amount of available RAM for applications is the sum of Free RAM and Inactive RAM. This will change as applications are opened and closed or change from active to inactive status. The Swap figure represents an estimate of the total amount of swap space required for VM if used, but does not necessarily indicate the actual size of the existing swap file. If you are really in need of more RAM that would be indicated by how frequently the system uses VM. If you open the Terminal and run the top command at the prompt you will find information reported on Pageins () and Pageouts (). Pageouts () is the important figure. If the value in the parentheses is 0 (zero) then OS X is not making instantaneous use of VM which means you have adequate physical RAM for the system with the applications you have loaded. If the figure in parentheses is running positive and your hard drive is constantly being used (thrashing) then you need more physical RAM.


    Adding RAM only makes it possible to run more programs concurrently.  It doesn't speed up the computer nor make games run faster.  What it can do is prevent the system from having to use disk-based VM when it runs out of RAM because you are trying to run too many applications concurrently or using applications that are extremely RAM dependent.  It will improve the performance of applications that run mostly in RAM or when loading programs.


    You can purchase memory upgrade kits at OWC specifically for your model.

  • natancaleb Level 1 (115 points)

    Thanks for the reply!


    Another Question.


    Is it possible to add 16GB (2x8GB) of ram to the stock 8GB (2x4GB)  that is already in the iMac?


    A total of 24GB (2x4GB, and 2x8GB)

  • yackem Level 1 (5 points)

    I have exactly the same configuration as you and I installed 2x8GB of ram.

    I now have 24GB showing. ALL GOOD.