iMac Memory in a Mini??

Discussion in 'Mac mini' started by rscott4563, Jul 15, 2008.

  1. rscott4563 macrumors member

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    Cumbria
    #1
    Quick question, can I use the 2x1gb of memory out of my new iMac in my new Mini? Can you put PC-6400 in a PC-5300 computer?

    If so it'll save me around £30 as I'm upgrading the iMac to 4gb and so will have the 2 sticks of PC-6400 spare.

    Cheers ;)
     
  2. minicoop503 macrumors regular

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    Feb 11, 2008
    #2
    As long it is the same size and type of memory. The speed doesn't really matter, it will just run at the slower speed.
     
  3. gehrbox macrumors 65816

    gehrbox

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    #3
    Not always the case. Some Macbook users tried PC2-6400 memory and it no worky. I read it here in MR, so it must be true:rolleyes:
     
  4. rscott4563 thread starter macrumors member

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    #4
    :confused: surely someone has done this before??

    I would have thought it would work as the memory should just run slower and cooler, both types of memory are physically the same aren't they?
     
  5. minicoop503 macrumors regular

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    #5
    Well it has always worked for me in my computers. There's no harm in trying at least.

    It should work. Just try and see.
     
  6. gehrbox macrumors 65816

    gehrbox

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    #6
    If you like risking the money, have at it. Why not buy what is required and eliminate the risk of wasting cash? You gain nothing by putting memory in the box that is out of spec. As has already been stated it will not speed anything up.
     
  7. rscott4563 thread starter macrumors member

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  8. rscott4563 thread starter macrumors member

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    #8
    So are you saying it could actually damage something??

    I'm not trying to speed anything up, it simply the fact that when I update the iMac to 4gb I'm going to have 2x1gb of perfectly good memory sat there doing nothing so doen't it make sense to use it in the Mini if it'll work??
     
  9. gehrbox macrumors 65816

    gehrbox

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    #9
    No it will not hurt anything. If you already own the memory then try it out.

    I just can't see buying memory for a system that might not work when you can buy the right stuff.
     
  10. rscott4563 thread starter macrumors member

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    #10
    Well thats exactly what I'd asked in my original post, I'd clearly stated that I already owned the memory...
     
  11. TBi macrumors 68030

    TBi

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    #11
    Well... actually the memory controller will run as fast as the memory running on it so it will run faster with 6400 (unless apple crippled it)
     
  12. H&Kie macrumors regular

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    Sep 19, 2004
    #12
    Well, just today I maxed up my iMac with 2x2 GB PC6400 RAM and put the old modules (2x1 GB PC6400) in my Macbook Core Duo, which originally housed 2x512 MB PC5300 RAM. Everything seems to work as it should. I tested the memory using Techtool and Rember and all tests passed just fine. Windows (using BootCamp) doesn't have issues either.

    Only thing is (as already stated), that the memory runs at 667 MHz instead of 800. Not to much of a problem...
     
  13. minicoop503 macrumors regular

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    Feb 11, 2008
    #13
    Thanks for reading the thread :)

    No it won't, it's always the memory that slows down. You can't just increase the memory bus speed, other than overclocking.
     
  14. TBi macrumors 68030

    TBi

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    #14
    My computer went to 800MHz automatically when i put in 800MHz modules.

    It's normal for a computer to run memory at it's rated speed if the motherboard chipset can handle it, so it can run the bus faster and even slower if needed.

    Running the memory bus speed faster doesn't increase the FSB speed so the computer doesn't run any faster (except for the boost given by faster memory).
     
  15. minicoop503 macrumors regular

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    Feb 11, 2008
    #15
    I'm sorry, but it doesn't work like that. If your motherboard only supports ddr2 533 ram, the fastest memory you can put in in ddr2 533. If you put in ddr2 800, it will run at 533 speeds. The same thing goes if you have two sticks of different speed ram. It will automatically downclock the faster ram to the slower ram's speed.

    Also, when you overclock a processor by increasing the FSB, that also increases the ram bus speed. I overclocked my Core 2 Duo e6300 from 1.8 to 3.01 ghz, and I had to change my ram bus multiplier to the lowest it could go, but my ram still runs at 860 mhz instead of 800. So, the FSB and ram speeds do correlate.
     
  16. TBi macrumors 68030

    TBi

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    #16
    That's what i said...
    The chipsets used in newer macbook support 800MHz ram but apple only provide 667MHz ram. There is no reason why these systems won't run the memory at 800MHz when you put in 800MHz RAM.

    It depends on the chipset and the BIOS. Some chipsets support the memory bus being held constant for changes in the FSB, most don't. Even if the chipset supports this then the BIOS might not. Yours doesn't, but that doesn't mean every other chipset works the same.

    Usually though the chipset changes the ram multiplier automatically to keep the memory running at it's rated speed. So basically my bios changed the memory multiplier so that the memory was now running at 800MHz while the FSB stayed the same.

    There is no reason a 800MHz supporting chipset in an Apple system cannot do the same.

    NOTE that i said supporting...
     

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