New 4GB DIMM's in iMAC Aluminum 20"?

Discussion in 'iMac' started by mindframe, Jun 29, 2008.

  1. mindframe macrumors newbie

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    #1
    Hi all,

    I have an iMac 2.0GHz Intel Core 2 Duo (20-inch) MA876LL. I'm big into desktop virtualization (using VMware fusion) so obviously the upgrade to 4GB is key. I have 1GB now mostly because I have been using it as an internet terminal, but it's still real slow.

    I would like to upgrade to 4GB- but I noticed they now sell 4GB DIMM's.

    Will the BIOS/MB refuse 2x4GB DIMM's for a total of 8GB? Any hacks or upgrades I could do to get 8GB in this machine?


    Also is the CPU socketed or soldered into the motherboard (I'm thinking the iMAC's use the same or similar motherboards as their laptops). If I could open this puppy up and drop in a 3GHZ C2Duo that would rock, but totally void warranty however.

    Just some questions. If I want a faster 20" maybe the 2.66ghz I might just have to sell the one I have now and buy a refurb or one on ebay....


    Thanks
    Pat
     
  2. gehrbox macrumors 65816

    gehrbox

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    #2
    It will not see beyond 4GB ram even if it would boot with that memory.
     
  3. mindframe thread starter macrumors newbie

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    #3
    Are there any aluminum imac 20" hacks? I heard about someone adding a 2nd HD internally... anything else?
     
  4. gehrbox macrumors 65816

    gehrbox

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    #4
    There's no place to put it internally unless you get rid of the DVD. Rather then go to all that trouble just buy an FW800 external drive.
     
  5. Techguy172 macrumors 68000

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    Ontario Canada
    #5
    It is possible the system will support the Memory no one has tested it yet and we remain unsure.
     
  6. mindframe thread starter macrumors newbie

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    #6
    what i might do is pickup one 4gb dimm, throw it in a slot and remove the 1gb. see if it boots.

    then add the 1gb and see if it sees 5GB.

    anyone know the command sequence to bring the boot phase into a "diag" mode kinda like the "ok" prompt on a sun workstation?
     
  7. losierp macrumors newbie

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    Jun 17, 2008
    #7
    If it does indeed boot then we know the iMac is capable of addressing more ten the 4GB of memory stated in the system specifications.

    My only concern with putting in 4GB and 1GB is that memory is supposed to be installed in matched pairs for optimal performance but it would be interesting to see if it works with more than 4GB of memory.
     
  8. gehrbox macrumors 65816

    gehrbox

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    #8
    Not really the Mac Mini will run with two 2GB sticks, but the computer will only be able to access 3GB of it.
     
  9. mindframe thread starter macrumors newbie

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    #9
    yah matched pairs provide the best performance, but if the system sees 5GB then I'll purchase another 4GB DIMM right away and probably take the 1GB out and sell it.

    If it doesn't work I'll just return it and act as a "clueless end user" lol


    i'll keep the thread updated on my progress. I'm going to buy one on Tuesday or so, it might get here after the holiday...

    If we can get 8GB in these puppies, that would make me VERY happy :)
     
  10. Tallest Skil macrumors P6

    Tallest Skil

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    #10
    That's because of the chipset. It can't address more than... wait... I was going somewhere with this... I HAD a side to this... I just can't figure out how to word it properly.

    Apple always understates the amount of RAM that you can put in their machines. The iMac DV can address 1GB, but Apple said the max was 512MB. Sometimes the limit they impose is due to the prohibitive cost of RAM at the time. Another example: the original Mac Pro was never touted to be able to use more than 16GB, but it, like the current one, can use 32GB. 4GB FB-DIMMs didn't exist at first, and when they started to come out, they were prohibitively expensive. Try ludicrously.
     
  11. MacFanatic08 macrumors member

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    #11
    If it does work, please post back here with some screenshots. :D
     
  12. NintendoFan macrumors regular

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    #12
    It should work, the chipset accepts 8GB total.
     
  13. mward333 macrumors 6502a

    mward333

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    #13
    Hey there mindframe, please keep us posted about this. I think that lots of people would be curious to know about this. Thank you for the question.... we look forward to some definitive feedback!
     
  14. cgingrich macrumors regular

    cgingrich

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    #14
    I would be interested to see if this works as well, please do tell us if it does!
     
  15. CanadaRAM macrumors G5

    CanadaRAM

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    #15
    No, Apple does not ALWAYS understate the RAM. It has happened in the past, but is not an indicator that it is Apple's policy to do with all machines.

    Apple's technical documents state unambiguously that the maximum readable device (chip) size is 1024 MBits, and the maximum readable number of devices on a module is 16. That means a maximum 2 GB module. Unless Apple is lying, that is the state of it until it can be shown to be wrong.

    OP -- the Intel Core2Duo Macs use SODIMMs, not DIMMs.
     
  16. proc macrumors member

    proc

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    #16
    This is something which has puzzled me and I sure would like to know as well: please post your progress and good luck!
     
  17. ayeying macrumors 601

    ayeying

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  18. idyll macrumors 6502

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    #18
    PLEASE let us know if this works! :D

    I'm on a Mac Pro with 8GB of memory and if the iMac could accept more than 4GB, even 5GB, I'd sell my Mac Pro and jump on the iMac in a heart beat. I know the previous iMacs could only support 3GB but if you put in 4GB it saw 3.3GB right?

    Maybe it will see 4.3GB?
     
  19. mindframe thread starter macrumors newbie

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    #19
    Here's where I found one initially:


    http://www.pricewatch.com/system_memory/ddr2-667_pc2-5300_4gb.htm

    Scroll down the page, it's a single stick 4GB 667mhz PC2-5300

    The only problem that I might have, is that these 4GB sticks are for servers. They use a technology called buffered ECC, to prevent internal memory errors. I am not sure if iMac's- or any mac for that matter, can use bufffered ECC memory- simply because the pin outs are different, I THINK. Since they are meant for servers, and "registered" memory is for "personal computers".

    Can anyone speak for hte pin outs of buffered ECC memory vs. registered memory? I don't wanna spend like $150 and find out it can't fit lol
     
  20. Cave Man macrumors 604

    Cave Man

    #20
    Why do you say that?
     
  21. Eric Lewis macrumors 68020

    Eric Lewis

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    #21

    thats desktop ram..not laptop
     
  22. Cave Man macrumors 604

    Cave Man

    #22
    If it's a Santa Rosa it should take 8 gigs, provided Apple hasn't disabled it. Here's what you need. It's now under $800 - what a bargain!
     
  23. ayeying macrumors 601

    ayeying

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    #23
    The iMac uses SO-DIMM (aka Laptop Memory or 200-pin) PC2-5300/6400 (Current) memory.
     
  24. mindframe thread starter macrumors newbie

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    #24
    Ahh crap. Well I guess that settles that! I should have bothered to read the instructions that came with the iMac on how to install memory, they probably would have showed a picture of the SODIMM ;) I figured since this machine is a "desktop" it would use desktop memory.

    So I guess all the iMac is is a Macbook Pro / Powerbook / whatever they're calling them now in a low foot print case with a big ass display?

    Thanks guys for saving me afew weeks of returns, RMA numbers, head aches, and restocking fees!

    Pat
     
  25. gehrbox macrumors 65816

    gehrbox

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    #25
    Because the manufacturer says these are the limitations http://www.apple.com/imac/specs/

    Lacking any other specification these are the facts as they stand now. If new technology becomes available after the specifications are created that permit larger memory then that will change things, but right now its limited to 4GB.
     

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