HT201191: Install memory in an iMac

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stvnjonsn

Q: I Can't put in 4 4gb modules, only 3.

If I put 4 - 4GB memory modules in my late '09 iMac it beeps and won't boot.  despite its being listed as upgradeable to 16gb I currently have 3 4Gb and a 2Gb installed and it boots right up.  any ideas why it won't take a 4th 4GB module?

iMac, OS X Yosemite (10.10.1), memory upgrade issues

Posted on Nov 19, 2014 6:49 PM

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Q: I Can't put in 4 4gb modules, only 3.

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  • by Kappy,

    Kappy Kappy Nov 19, 2014 7:02 PM in response to stvnjonsn
    Level 10 (270,309 points)
    Desktops
    Nov 19, 2014 7:02 PM in response to stvnjonsn

    Does this occur regardless of the slot or the module?

  • by Mike Sombrio,

    Mike Sombrio Mike Sombrio Nov 19, 2014 7:10 PM in response to stvnjonsn
    Level 6 (17,201 points)
    Apple Watch
    Nov 19, 2014 7:10 PM in response to stvnjonsn

    Does the iMac boot with just 3x4 installed? Without the original 2gb module in the fourth slot.

  • by Allan Jones,

    Allan Jones Allan Jones Nov 19, 2014 7:49 PM in response to stvnjonsn
    Level 8 (35,044 points)
    iPad
    Nov 19, 2014 7:49 PM in response to stvnjonsn

    What RAM did you buy? Intel macs can be picky about RAM and often fail to work properly with "value" RAM from some vendors.

  • by stvnjonsn,

    stvnjonsn stvnjonsn Nov 19, 2014 8:03 PM in response to Kappy
    Level 1 (0 points)
    Nov 19, 2014 8:03 PM in response to Kappy

    Yes tried all configs and modules to rule out a bad module or slot.

  • by stvnjonsn,

    stvnjonsn stvnjonsn Nov 19, 2014 8:04 PM in response to Allan Jones
    Level 1 (0 points)
    Nov 19, 2014 8:04 PM in response to Allan Jones

    Bought PNY DDR3 PC-1066  4GB 2 packs

  • by stvnjonsn,

    stvnjonsn stvnjonsn Nov 19, 2014 9:00 PM in response to Mike Sombrio
    Level 1 (0 points)
    Nov 19, 2014 9:00 PM in response to Mike Sombrio

    Yes, 3x4 w the 2 installed works.  using it as we speek

  • by MichelPM,

    MichelPM MichelPM Nov 19, 2014 11:44 PM in response to stvnjonsn
    Level 6 (13,660 points)
    iPad
    Nov 19, 2014 11:44 PM in response to stvnjonsn

    PNY RAM may not be reliable or spec'd properly for Macs.

    You cannot buy RAM for Macs from local electronics and computer stores.

    No one local will carry Mac RAM that is the right spec'd RAM.

    Return it for a full refund.

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

  • by Mike Sombrio,

    Mike Sombrio Mike Sombrio Nov 20, 2014 3:39 AM in response to stvnjonsn
    Level 6 (17,201 points)
    Apple Watch
    Nov 20, 2014 3:39 AM in response to stvnjonsn

    stvnjonsn wrote:

     

    Yes, 3x4 w the 2 installed works.  using it as we speek

    Specifically what I asked was does it boot with 3x4 installed WITHOUT the 2 installed? That's an important piece of information because the 2gb module will force the others, if they're the wrong speed to run at a lower speed and possibly work. If it doesn't boot without the 2 installed you should return them and get ram that is manufactured to tighter specs. Some of these ( I call them bargain basement brands ) manufacturers play fast and loose with the specs because PC's generally can handle a ram module that isn't exactly what it's advertised as, Macs can't.

    In order to get ram that is guarenteed to work with your Mac you should purchase from either Crucial http://www.crucial.com

    or OWC http://eshop.macsales.com

    The temptation to save a few dollars by purchasing ram from other sources is sometimes rewarded with Macs that won't boot or kernel panics and corrupt data.

  • by stvnjonsn,

    stvnjonsn stvnjonsn Nov 20, 2014 6:31 AM in response to Mike Sombrio
    Level 1 (0 points)
    Nov 20, 2014 6:31 AM in response to Mike Sombrio

    It does boot without the 2gb, in 2x or 3x by configs.  if i add a 4th it won't boot until I remove ANY of the remaining modules.  weirdest thing.  I was tempted to get some different modules, but except for this quirk the machine runs flawless. I tried removing a chip from pair 1 and par 2 (they came shipped as pairs) I tried with each chip individual all with no issues.  all show up correctly in the "about this machine" memory tab.

  • by stvnjonsn,

    stvnjonsn stvnjonsn Nov 20, 2014 6:33 AM in response to MichelPM
    Level 1 (0 points)
    Nov 20, 2014 6:33 AM in response to MichelPM

    PNY packaged it with the Mac logo.  It came from amazon as the correct ram for this machine.  Is there a certification beyond the mac logo I need to be looking for?

  • by stvnjonsn,

    stvnjonsn stvnjonsn Nov 20, 2014 6:46 AM in response to Mike Sombrio
    Level 1 (0 points)
    Nov 20, 2014 6:46 AM in response to Mike Sombrio

    Memory.jpg

  • by Mike Sombrio,

    Mike Sombrio Mike Sombrio Nov 20, 2014 11:28 AM in response to stvnjonsn
    Level 6 (17,201 points)
    Apple Watch
    Nov 20, 2014 11:28 AM in response to stvnjonsn

    PNY is one of the bargain basement brands that I said play fast and loose with their specs. your Mac requires ram that is EXACTLY 1066mHz, those state that they'll work with systems running at 1066 AND 1333.....they could be running practically any speed between those two. you should return those and exchange them for Crucial ram from Amazon for $1 less.

  • by GeoJoe1,

    GeoJoe1 GeoJoe1 Nov 22, 2014 2:46 PM in response to Mike Sombrio
    Level 1 (0 points)
    Nov 22, 2014 2:46 PM in response to Mike Sombrio

    Mike,

     

    I think this answers my questions too!  I have a Mid 2007 iMac and purchased the same brand of RAM, 2 x 2GB.  With both new modules in, the iMac won't boot.  With the original 1GB and one of the new 2GB modules for a total of three GB, iMac works and sees all three GB. I ordered RAM from Crucial and we'll see if that works.  Thanks!