10 Replies Latest reply: Mar 8, 2014 7:04 PM by rkaufmann87
Niku Level 2 (285 points)

I was thinking of increasing the memory on my iMac. I found  a site that explains everything I need to know, but I found that the 27" version was made in 2010, 2011, 2012, and 2013. How can I determine which year-model mine is?

iDVD 7.1.1 (1150)
  • jwukitsch Level 2 (225 points)

    Click the Apple in the top left corner > About this Mac > More info > It should pop up saying iMac Late/Early (year)

  • rkaufmann87 Level 9 (55,308 points)

    Actually it takes a bit more. Click the Apple Symbol in the upper left of your display, choose About This Mac and if you are using OS X 10.7.x Lion or later then click More Info and you will see what year your device is.

  • Niku Level 2 (285 points)

    Thanks, I've been there before, but I had never noticed that information. I now know that I have a late model 2009, which isn't even among the years mentioned in the list I read. I hope this doesn't mean that I won't be able to increase my memory from its present 4GB. I just don't like the idea of my girlfriend wiping the floor with me with the TABLET computer she just bought. I've forgotten exactly how much memory it has, but it's in the double digits. I had never heard of it, but I guess that's my fault. It's a Surface Pro.


    I guess that's just the way it goes with computers. You can never stay ahead for very long.


    Message was edited by: Niku

  • rkaufmann87 Level 9 (55,308 points)

    A late 2009 27" iMac can accomodate up-to 32GB of RAM. If you plan on upgrading visit Crucial or OWC (www.macsales.com) and order. These are two very reputable vendors.

  • Niku Level 2 (285 points)

    That's interesting--and confusing. As you can see from my recent posting, my source had said that the maximum memory for my computer was 16GB. I guess that was true when that posting was made but  advances in chip technology made those words obsolete. Thanks for saving me from a mistaken but avoidable purchase.

  • K Shaffer Level 6 (12,635 points)

    With your model number and serial number you can find out more exactly what

    computer you have, the specifications, upgrade ceilings, what it shipped with

    and a few other dozen things...


    IF the computer is an iMac (27-inch, Late 2009) model, RAM specs are:


    Maximum Memory32 GB (Core i5 or Core i7 Actual) 16 GB (Apple)
    Memory Slots4 - 204-pin PC3-8500 (1066 MHz) DDR3 SO-DIMM

    {as per specs from http://mactracker.ca download database}


    •iMac: How to remove or install memory



    The general range of 'Late 2009' 27" iMac series could have a Core2Duo,

    or a Core i5, or Core i7 processor, and one of a few graphic processors.


    Model IdentifieriMac10,1 (Core 2 Duo) iMac11,1 (Core i5, i7)
    Model NumberA1312
    EMC2309 (Core 2 Duo) 2374 (Core i5, i7)
    Order NumberMB952LL/A (3.06 GHz), MB953LL/A (2.66 GHz)


    If you wanted to follow the model number and serial number further, so

    as to then later look into MacTracker &/or Everymac.com data, then a

    search by Model number or Serial number could be a path. This site is

    said to be a secure (lock icon) http:// page, and looks OK.


    •Identify your Mac - Lookup your unit by Apple model or serial number:



    Anyway, if you get quality RAM upgrade chips that totally match the

    specifications set by Apple, from either OWC macsales or Crucial,

    these would likely help out somewhat.


    Also check into a good backup solution, perhaps with two external HDD

    units, one for TimeMachine and another with partition for OS X Clone as

    well as space for additional storage off the computers hard disk drive.


    Good luck & happy computing!

  • MichelPM Level 6 (11,450 points)

    I am not sure about rkaufmann's response to you.

    I have a 2009, 27 inch screen iMac and as far as I am aware, the maximum RAM for that year and model is 16 GBs.

    Correct and reliable Mac RAM can be purchased from online Mac RAM sources Crucial memory or OWC (macsales.com).

    The Core2Duo models can only take 16 GBs of RAM. This is what I have.

    The quad core i5 and i7 models are the only ones that can take 32 GBs of RAM.

  • K Shaffer Level 6 (12,635 points)

    Could the 'Core 2 Duo' build in that model number, use less RAM

    total than the other two models, which have the Core i5 & Core i7?


    There are some questions that arise when looking at partial info.

    An identification by serial number may show more exact detail.


    Good luck & happy computing!


    edited 12:26PM local - you were also replying as I was

  • Baby Boomer (USofA) Level 9 (57,297 points)

    The years of Macs can be quite confusing.  I purchased a spanking brand new iMac in late Jan (2013).  Didn't receive it until March 2013.  Up until a few months ago I just knew I had either an early 2013 or just a plain old 2013 iMac.  Guess what?  It's a late 2012.   Imagine my surprise. 


    Not quite sure what the differences are if any.  Never really checked into it.
















    AD Siggy.gif

  • rkaufmann87 Level 9 (55,308 points)

    According to OWC a late 2009 27" iMac can accomodate 32 GB. Here is the link: