24GB RAM? Late 2012 27" iMac

Discussion in 'iMac' started by virginblue4, Feb 20, 2013.

  1. virginblue4 macrumors 68000

    virginblue4

    Joined:
    Apr 15, 2012
    Location:
    United Kingdom
    #1
    I plan on purchasing 16GB crucial RAM for my late 2012 27" iMac when it arrives.

    I don't plan on getting rid of the 8GB stock RAM that the iMac comes with. Can I just combine 2 8GB sticks with 2 4GB sticks?

    Will there be any performance problems or will it be detrimental to the long term health of my iMac?

    Many thanks!
     
  2. highlightshadow macrumors regular

    Joined:
    Oct 11, 2012
    #2
    Thats exactly what i'm running ... seems fine to me :)
     
  3. Shane1905 macrumors regular

    Joined:
    May 21, 2012
    Location:
    UK
    #3
    Same as above. Been running it since day one back at the beginning of January. No problems at all
     
  4. NYY FaN macrumors 6502

    NYY FaN

    Joined:
    Jun 22, 2009
    Location:
    New York
    #4
    I'm running 24GB also, no issues. Just put the 8GB sticks into the 2 empty slots and you're set.
     
  5. virginblue4 thread starter macrumors 68000

    virginblue4

    Joined:
    Apr 15, 2012
    Location:
    United Kingdom
    #5
    Great, thanks for the replies! Looks like I will be doing this then :)
     
  6. zonesey macrumors member

    Joined:
    Jul 13, 2009
    Location:
    Finland
    #6
  7. jtrainor56 macrumors regular

    jtrainor56

    Joined:
    Oct 23, 2010
    Location:
    Sinking Spring, Pennsylvania
    #7
    I have been running 24 gig since xmas. No drop in speed either.
     
  8. seanm9 macrumors regular

    Joined:
    Dec 29, 2007
    Location:
    Cape Cod, MA
    #8
    There is so much wrong with this post it is not even funny...
    As long as you buy unbuffered non-ecc ddr3-1600 with a cl of 11 you are good... If you buy faster latency ram (cl 10 or cl 9) it can slow the bus speed to 1333 mhz... Crucial's website will tell you what ram to buy to match the stock ram...
     
  9. zonesey macrumors member

    Joined:
    Jul 13, 2009
    Location:
    Finland
    #9
    True, but the point is that the bus speed can be decreased to 1333... So, be careful what you buy :)
     
  10. virginblue4 thread starter macrumors 68000

    virginblue4

    Joined:
    Apr 15, 2012
    Location:
    United Kingdom
    #10
    I assume this is the correct RAM?

    http://www.crucial.com/uk/store/mpartspecs.aspx?mtbpoid=CFFEC046A5CA7304
     
  11. zonesey macrumors member

    Joined:
    Jul 13, 2009
    Location:
    Finland
    #11
    Personally, I wanted to max out the RAM (32GB), so I didn't (need to) worry about compatibility with the Apple RAM.

    It doesn't seem to be all that simple all the time. See this for example:
    https://discussions.apple.com/message/21056039#21056039

    Anyway, hope my posts help... You never know what kind of flak you might get if you open your mouth on this forum :D
     
  12. iMaxIt macrumors newbie

    Joined:
    Feb 4, 2013
    #12
  13. highlightshadow macrumors regular

    Joined:
    Oct 11, 2012
    #13

    Attached Files:

  14. gaddster macrumors member

    Joined:
    Jan 26, 2013
    Location:
    liverpool, england
    #14
    I have just added 16gb Crucial ram to my new iMac 27.. although I read on here somewhere to put the 2 x 4gb ram in the spare 2 slots and insert the 2 x 8gb ram in the 4gb slots (if that makes sense). So my setup is 4,8,4,8 as you look at it from behind

    Works great so far
     
  15. Hexley macrumors 6502a

    Joined:
    Jun 10, 2009
    #15
    I'm running on 2x8GB and 2x4GB right now and my RAM speed drops to 1333MHz. Not to worry as I ordered another 2x8GB to make mine 32GB at 1600MHz.

    Moving my 8GB to a 2010 13" MBPro. Hopefully it takes.
     
  16. robjulo macrumors 65816

    Joined:
    Jul 16, 2010
    #16
    Your post said "there will be a decrease" not "can be if you get the wrong kind", hence the erroneous information.

    If the OP uses the crucial adviser, there will not be an issue. From another thread, the recommended procedure from Apple is to remove the two 4 gig sticks, replace them with the 8 gig sticks, then put the 4 gig in the remaining two slots.

    That is what I did. There is no decrease in speed, system sees 24gig and I have not run into issues.
     
  17. gaddster macrumors member

    Joined:
    Jan 26, 2013
    Location:
    liverpool, england
    #17
    This is what I did, cant go wrong unless crucials website is wrong..

    PS how are you guys monitoring the ram speed to see what you are getting?
     
  18. robjulo macrumors 65816

    Joined:
    Jul 16, 2010
    #18
    Apple logo in top left > About this Mac > More Info > System Report > Memory

    This will show you the slots used, size of the memory and speed
     
  19. gaddster macrumors member

    Joined:
    Jan 26, 2013
    Location:
    liverpool, england
    #19
    Great thanks

    Yep, mine stating a glorious 24gb at 1600MHz

    Out of curiosity, is there any difference with the way i have my slots i.e.

    Bank 0 8gb
    Bank 1 8gb
    Bank 0 4gb
    Bank 1 4gb
     
  20. robjulo macrumors 65816

    Joined:
    Jul 16, 2010
    #20
    I'll look when I get home tonight to see how mine are laid out.

    I did do the recommended process (at least the post I referred to indicated it was the Apple recommended process), in that I removed the 4 Gig Sticks, replaced those sticks with the 8 Gig sticks in the slots that previously contained those 4 Gig Sticks and then put the 4 Gig Sticks back in the remaining open slots.
     
  21. gaddster macrumors member

    Joined:
    Jan 26, 2013
    Location:
    liverpool, england
    #21
    Cool thats what I did, so think I have done it right :D
     
  22. Felder71 macrumors member

    Joined:
    Aug 26, 2008
    #22
    I ordered this:

    http://amzn.com/B008LTBJFW

    And put them both into the empty slots. Didn't move the Apple RAM.

    My system says 24 GB, all running at 1600 Mhz (or whatever unit it is).

    No crashes or issues in the past few days.
     
  23. WilliamDu macrumors regular

    Joined:
    May 22, 2012
    #23
    RAM/slot configuration for 24GB

    This is the correct RAM placement.

    The new RAM must be inserted where the original Apple RAM was located.

    The processor goes to those slots first, so it will see and use the new 16GB first and not use the old 8GB unless needed for more than 16.
     
  24. robjulo macrumors 65816

    Joined:
    Jul 16, 2010
    #24
    Mine is showing the same as yours.
     
  25. highlightshadow macrumors regular

    Joined:
    Oct 11, 2012
    #25
    I moved 1 of the 4GB sticks into the other bank before installing mine ... so i have the banks matched .... doesn't make massive difference though
     

Share This Page