Can the Late 2009 27" iMac handle 32GB of RAM?

Discussion in 'iMac' started by gatortpk, Feb 21, 2012.

  1. macrumors 6502

    Joined:
    Nov 25, 2003
    Location:
    Melbourne, FL
    #1
    I have read that the 2010 and later 27" iMac models can support 32GB of RAM with the new 8GB DDR3 SO-DIMMs. That would be the iMac models 11,2 / 11,3 / 12,1 / 12,2. (I'm assuming the 12,1 and 12,2 also)

    I have the late 2009 27" iMac with the Quad Core i7-860 at 2.8GHz. It's the iMac 11,1. I was wondering if anyone has tried 32 GB of RAM in that model? (or even 2x8GB or 20GB/24GB/28GB combinations)

    I have found that many of the things that were thought to be new with the 2010 models also work with the late 2009 models. (Such as audio through the Mini-DisplayPort and handling of the SDXC SD Cards does work on the late 2009 iMac as well, possibly through a firmware update since 2010?)

    Anyone with knowledge of the memory controllers or experience with this specifically, any comments would be greatly appreciated!

    (Also, the cost of these 8GB SO-DIMMs have come down to lower than the 4GB SO-DIMMs that I bought 2 years ago to bring it up to 16 GB. And I easily use over 12GB of RAM continuously everyday, I just hate it when I start to use Swap memory, the HDD for virtual memory. So I'm aware how much 32GB is, and that I could use it! So please, no comments about: Why or How could you use/need 32GB of memory! :) )
     
  2. macrumors 6502a

    AcesHigh87

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    New Brunswick, Canada
    #2
  3. thread starter macrumors 6502

    Joined:
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    #3
    Yes, I have seen that. I also saw:

    http://eshop.macsales.com/item/Other World Computing/1333DDR3S32S/

    It does not say anything about the 2009 models, but history has shown that sometimes a model isn't mentioned because it simply wasn't tested, not because is won't work. Hopefully it's possible. I'm just trying to get confirmation before buying a couple of 8GB SO-DIMMs to start with.

    Thanks for the input! :)
     
  4. thread starter macrumors 6502

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    Nov 25, 2003
    Location:
    Melbourne, FL
    #4
    There is one thing I forgot to mention and notice, is that OWC is selling 1333MHz DDR3 for the later model iMacs. The Late 2009 iMac takes 1066MHz DDR3. I believe the late 2009 iMac can take 1333MHz DDR3 under very specific situations, I think it has to do with the CL, CAS numbers. They need to be 7 instead of 9.

    I'm getting this from something I read a while ago. Can anyone confirm?

    This is also possibly the reason that OWC doesn't list the late 2009 model with it's 32GB RAM package.
     
  5. macrumors 6502a

    AcesHigh87

    Joined:
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    New Brunswick, Canada
    #5
    I would suggest you send them an email. They're pretty good for getting back to customers and would likely be able to tell you if it would work and why it wouldn't if that's the case.
     
  6. macrumors 6502a

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    Location:
    Essex, england
    #6
    Wirelessly posted (Mozilla/5.0 (iPhone; CPU iPhone OS 5_0_1 like Mac OS X) AppleWebKit/534.46 (KHTML, like Gecko) Version/5.1 Mobile/9A405 Safari/7534.48.3)

    You can try everymac.com if all else fails. They usually put down every mac model up till the latest ones and usually give out the specs, the max upgrades for it and it's price
     
  7. macrumors regular

    Joined:
    Jun 5, 2010
    #7
    AFAIK, it can only hold 16 Gbs. I bought 16 via OWC and installed them.
     
  8. macrumors Westmere

    GGJstudios

    Joined:
    May 16, 2008
    #8
    You can find specs on all Apple products, including maximum RAM:
     
  9. thread starter macrumors 6502

    Joined:
    Nov 25, 2003
    Location:
    Melbourne, FL
    #9
    Thanks for the links, and another question about CL ratings?

    Thanks for the links! everymac.com is one of my favorite websites. I use it almost everyday. It has been a great source for actual maximum memory. It's usually the first to report a new maximum.

    They even sometimes provide links to some articles regarding any prior confusion (such as 6GB or 8GB in the Unibody MacBooks? It was finally discovered that Apple quietly released an unrelated FirmWare update that allowed those MacBooks to work fine with 8GB of RAM)

    The other websites I hadn't tried, and the Apple Specs website was impressive. I have never seen Apple be so comprehensive about their specs! Though they still won't report higher actual RAM maximums on known working configurations.

    Unfortunately, no one seems to have confirmed that 32GB will work. I hope the only hold back on 32GB of RAM in an iMac 11,1 (late 2009) is finding single 8GB PC3-8500 SODIMMs, or 8GB PC3-10666 SODIMMs with a CAS latency of 7 (instead of 9).

    Does anyone know why a 0.37 ns (nanosecond) greater latency on the first word read from RAM really matters that much. It's oh so close compared to the much greater latency differences that doesn't seem to matter with many other memory controllers. I'm talking the difference between 13.13 ns latency with DDR3-1066 (CL 7) and 13.50 ns latency with DDR-1333 (CL 9) on first word timing. (Actually, I just noticed that many different memory speed modules have the same latency on the first word read, such as DDR and DDR2, but not with SDR! And the PC133 is a whole 2.5 ns longer than PC100, and those computers didn't mind PC133 when they are designed for PC100, but I guess we're talking ancient history and apples and oranges?)

    How about another question, can memory controllers generally always accept different speed memory as long as the CAS latency on the first word read is shorter?

    Ah, I just figured that, when accounting that faster RAM slows down to the bus speed of the designed RAM speed, the CL number comes out to the exact same with the same first word read latency timing! I guess that's a "duh!" to memory experts.

    Still my question applies, can I use a DDR3-1333 with a CL of 6 instead of DDR3-1066 with a CL 7 as the designed specs call for? It's a shorter CAS latency even though it's a faster chip (that usually has a higher CL rating that would make it incompatible).
     
  10. macrumors Westmere

    GGJstudios

    Joined:
    May 16, 2008
    #10
    For the Mid-2010 iMacs, the 21.5" supports up to 16GB of RAM. The Mid-2010 27", as well as all later iMacs (21.5" and 27") all support 32GB.
     
  11. thread starter macrumors 6502

    Joined:
    Nov 25, 2003
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    Melbourne, FL
    #11
    21.5" iMac vs earlier 27" iMac memory controller qualification?

    Are you suggesting that the 2010 21.5" iMacs have the same memory controller as the late 2009 27" iMacs, and therefore that's why both only support 16GB of RAM?

    And that the 2010 27" iMacs can support 32GB of RAM because they have a (better) different memory controller than the same year 2010 21.5" iMac that only supports 16GB of RAM?
     
  12. aceyriot, Aug 15, 2012
    Last edited: Aug 15, 2012

    macrumors newbie

    Joined:
    Apr 28, 2011
    #12
    i can confirm that 1333 works in the 2009 imac as long as you meet the following conditions: its all about front side bus.
    the i5 and i7 models are intel dmi which means their fsb tops out at 2.5gt/s(giga-transfers per second) essentially equating to(as i understand it) 3600mhz+
    theoretically that means that if you can find 204 pin memory beyond 1333mhz it should work as well ...but, as im told, it is locked at 1333mhz for stability all the way up until the current generation (2012) models

    1333mhz is fully tested and working with my 2009 2.8gHz i7 imac
    i have full memory speed and it runs like a dream.its just amazing! honestly the only thing that im jealous of in the new models is the thunderbolt but who even has anything beyond a hard drive that works with that yet?

    1333mhz will in fact also run in the 3.33gHz (only) core 2 duo models but it is rumored to be a total crapshoot in regards to the manufacturers of the ram themselves
    while the memory will be recognized and run without a hiccup it may end up being limited functionally to 1067mHz
    i showed a friend of mine my i7 imac and he chose to grab the c2d 3.33 model.
    at first he failed to get the memory recognized as 1333 until he swapped out some samsung mem for kingston! (strange, right?) luckily if you live in california fry's electronics is REALLY good about returns. i'm sure if you prefer to go the website route you should still be able to swap and experiment just the same.
    but there you have it. 1333 works in every i5/and i7 imacs and even a few core2duo 2009's

    now as for cas latency
    CL is seriously meaningless in this situation. it equates to fractions of fractions in regards to performance, this is also one place(of many places)where whatever minor bump in speed you are expecting will not only be unnoticable but honestly you are gilding the lily, the cost is heavier than the benefits. cl9 is common and cheap and totally fine and there arent too many options to begin with as the clock speed is all that really matters at this point in technological advancement. but if you really must know: cl9 shows response times of 10.5 nanoseconds compared to 9 nanoseconds in cl7. totally arbitrary and not worth giving two craps about. not only does cas latency not matter on a perfomance standpoint but your mac wont care what the latency is. cl7 works, cl9 works, mix and match all you like they will run at the higher latency (obviously) with no compatibility issues. as long as it fits the above criteria it will work...204 pin so-dimm pc3-10600 1.35v and 1.5v work at their respective charges simple as that.
     
  13. macrumors newbie

    Joined:
    Apr 28, 2011
    #13
    i forgot to mention. after my success with 4X4gb i went and tried 2X8gb dimms and no dice. no memory found at all. wouldnt even boot. so that alone should tell you 32gb is a bust where the 2009's are concerned but really 16gb is still quite impressive for me and ostentatious to just about anyone else. and really who needs more? i use logic pro with many many rtas and vsti's running in rtas modules, many soft synths and LOTS of high quality samples and i havent used so much as HALF of that memory yet, (the processor doesnt even break a sweat (wish i could say the same about my old g4...really wanted to squeeze every dollar out of that one).right now i have firefox open with 20 tabs, itunes playing, a torrent client (downloading public domain torrents only *cough*) and vlc up with a movie on pause and i only have a measly 2.41gb active right now with a total of 5.35gb 'in use' and
    10.65 completely free...couldn't be happier i probably wont need a major upgrade for 5 more years or more and even then ill probably swap out my superdrive for a ssd before i decide to pull the trigger on a new one. (just a bit more personal info, i tend to pay out the ass so my macs keep their usefullness longer and i recommend that method to everyone i talk shop with, my old art teacher still runs an old tibook and she hasnt needed to do much more than drop a new hard drive in there, food for thought)
     
  14. macrumors newbie

    Joined:
    Jul 16, 2012
    #14
    Can you tell us what RAM you purchased that's working at 1333MHz?
     
  15. coreytrice, Sep 10, 2012
    Last edited: Sep 10, 2012

    macrumors newbie

    Joined:
    Sep 10, 2012
    #15
    Ram

    Komputerbay's 1333MHz doesn't work with the late 2009 iMac. I just bought some the other day, installed four 4GB chips and no joy. I had read somewhere that the iMac would just lower the clock speed on the ram if it was incompatible. I thought maybe it was that one set was bad, but only putting one set in didn't work either. Finally, I tried two new Komputerbay 4GB and the two Apple 2GB chips and it turned right on. It showed the clock speed as set at 1066MHz with 12GB, so I pulled one of the Apple 2GB chips and replaced it with a new Komputerbay 4GB chip and again it came on showing 14GB and 1066MHz. I guess it just needs at least one chip with the correct speed installed to turn on, so instead I decided to just order four 4GB 1066MHz chips and send the others back.
     
  16. macrumors 6502a

    ImAlwaysRight

    Joined:
    Jul 10, 2002
    #16
    Yes, 32GB works just fine in a 2009 27" Quad i7. Will even run at 1333MHz instead of 1066MHz.

    [​IMG]

    (I cut off the screen capture to leave out my serial number.)
     

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  17. thread starter macrumors 6502

    Joined:
    Nov 25, 2003
    Location:
    Melbourne, FL
    #17
    Wow, that's exactly what I was looking for! I think the reason I was asking was because I couldn't find any 8GB 1067MHz SODIMMs so I was wondering if I could get the 8GB 1333MHz SODIMMs to work in my 2009 27" iMac. What configuration is are the SODIMMs? i.e. what gigabit chips or arrangement, if that matters?

    I know people have been doing that with the 2010 and later model iMacs. But, this is the first nice confirmation I've seen for a late 2009 iMac with 32 GB of RAM. Thanks!
     
  18. macrumors 65816

    MacSince1990

    Joined:
    Oct 6, 2009
    #18
    It identifies the memory modules properly at 1.33 GHz, that doesn't mean they're actually running that fast (they're not).

    Just like with every other computer in history, you can run faster RAM of the same type, but it'll run at the same speed as the memory controller.
     
  19. macrumors member

    Joined:
    Mar 12, 2011
    Location:
    Ashland, Oregon
    #19
    Can anyone who has done this be sure to give the rest of us a few more details on exactly what to do and buy so that we can have this 32 Gig configuration without any unexpected hiccups? Thanks!
     
  20. macrumors newbie

    Joined:
    Oct 7, 2012
    #20
    You can consider using Kingston RAM

    Hi

    I am running on the following Kingston RAM at 1333mhz , tested with Rember app , 100% error free .
     

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  21. macrumors newbie

    Joined:
    Feb 18, 2011
    #21
    Does anyone know why the iMac 21.5" mid 2010 with 3.6 i5 can't also run 32gb of ram?
     
  22. macrumors Westmere

    GGJstudios

    Joined:
    May 16, 2008
    #22
    Even the 27" 3.6 released later that year only officially supports 16GB, but it has been found it will actually support 32GB. I haven't seen any information explaining why yours won't support 32GB, but as everymac.com shows a max of 16GB for yours, I'd trust that.
     
  23. macrumors newbie

    Joined:
    Feb 18, 2011
    #23
    Does anyone know where everymac.com gets the data from? I just don't realize what causes the memory limitation? Is it the cases ability to dissipate the heat, or what?
     
  24. macrumors Westmere

    GGJstudios

    Joined:
    May 16, 2008
    #24
    No, RAM limitations frequently have to to with limits on how much memory can be addressed by an Intel chipset. Firmware versions can also play a role. RAM doesn't generate a significant impact on heat. The CPU and GPU are the two primary heat sources.
     
  25. azBoB, Oct 18, 2012
    Last edited: Oct 18, 2012

    macrumors newbie

    Joined:
    Feb 18, 2011
    #25
    I read on a seperate thread here that the OS limit for memory addressing is 96GB.

    So does everymac.com try different memory configurations, or do they just repeat apple specs, and include reported successes with attempted memory upgrades?
     

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