4 Replies Latest reply: Oct 16, 2012 11:35 AM by seventy one
Kikitsa Level 1 Level 1

I upgraded to 16 mb of ram and after 10 minutes my computer freezes, and ideas?  I have an imac mid 2011 21 inch.


iMac, OS X Mountain Lion (10.8.2)
Solved by John Galt on Oct 16, 2012 10:53 AM Solved
Paul_31 wrote: Seems that iMacs a very picky about the make of RAM installed.  Just bear in mind that thread concerns the 27" model. I only read a few pages but could find no specific references to the 21.5" model. 16 GB should not be a problem in a 21.5" iMac. I have the exact same mid-2011 model as the OP and am using 16 GB memory from Crucial. Prior to installing it I tried a 16 GB Kingston memory kit, which resulted in problems similar to those described in that thread.
Reply by John Galt on Oct 16, 2012 9:43 AM Helpful
Cause and effect points to out-of-spec memory. Run Apple Hardware Test. Run the extended tests.    Using Apple Hardware Test http://support.apple.com/kb/HT1509 If it fails the memory tests, remove the memory and re-seat it. The sockets are very "tight". Run AHT again. If it still fails, replace your original memory. If it works, you found the problem. Buy Mac memory from Crucial or OWC / MacSales.

All replies

  • John Galt Level 8 Level 8

    Cause and effect points to out-of-spec memory.

     

    Run Apple Hardware Test. Run the extended tests.

     

      Using Apple Hardware Test


    867df1db96809188506cddec00dded4f.jpeg

     

    If it fails the memory tests, remove the memory and re-seat it. The sockets are very "tight". Run AHT again.

     

    If it still fails, replace your original memory. If it works, you found the problem. Buy Mac memory from Crucial or OWC / MacSales.

  • Paul_31 Level 6 Level 6

    May not be the same issue but could be related, but there is a long thread here about problems after installing 16gb of RAM:

    https://discussions.apple.com/thread/2473276?tstart=630

     

    Seems that iMacs a very picky about the make of RAM installed. A workaround is to drop down to 12gb with the proper solution being to only install certain makes of RAM - Samsung being one plus one or two others. Worth a read through the thread.

  • John Galt Level 8 Level 8

    Paul_31 wrote:

     

    Seems that iMacs a very picky about the make of RAM installed.

     

    Just bear in mind that thread concerns the 27" model. I only read a few pages but could find no specific references to the 21.5" model.

     

    16 GB should not be a problem in a 21.5" iMac. I have the exact same mid-2011 model as the OP and am using 16 GB memory from Crucial. Prior to installing it I tried a 16 GB Kingston memory kit, which resulted in problems similar to those described in that thread.

  • seventy one Level 6 Level 6
    expertise.peripherals
    Peripherals

    And the key word, John, is Kingston.  Your earlier recommendations are right; Crucial if you are in Europe and OWC if you are in North America.