is ddr2 ram backwards compatible with a ddr spec machine?

Discussion in 'Mac Basics and Help' started by Megatron, Dec 1, 2007.

  1. Megatron macrumors regular

    Joined:
    Nov 19, 2005
    #1
    Hello,

    I have a ddr2-667 PC5300 ram stick.

    Can I use that in a machine that uses ddr-266 PC2100 ram?

    I thought I remember reading ram was backwards compatible but I just wanted to ask the experts.

    Thanks!
     
  2. rogersmj macrumors 68020

    rogersmj

    Joined:
    Sep 10, 2006
    Location:
    Indianapolis, IN
    #2
    No, they are definitely not backwards compatible. The notches are in different positions just to make sure you don't try it.
     
  3. Megatron thread starter macrumors regular

    Joined:
    Nov 19, 2005
    #3
    Haha good point! The machine is a friend's machine so I hadn't even looked at what the notches look like.

    So is it backwards compatible if it is the same number ddr#? I.e. ddr2 5300 and ddr2 2700?
     
  4. skuzzy macrumors member

    Joined:
    Dec 1, 2007
    Location:
    Cape Town, SA
    #4
    Simple answer: no

    *edit: It's a lot like trying to make a SATA hard drive work with an IDE interface.
     
  5. CanadaRAM macrumors G5

    CanadaRAM

    Joined:
    Oct 11, 2004
    Location:
    On the Left Coast - Victoria BC Canada
    #5
    No such thing as DDR2-2700. The only similarity in numbers is PC3200 (DDR-400) and PC2-3200 (DDR2-400 which is rarely seen outside of servers)
    Give it up - DDR and DDR2 are physically and electrically incompatible

    sk: SATA / IDE isn't that great of an example, because you can get format convertors for drives, but not RAM.
     
  6. Megatron thread starter macrumors regular

    Joined:
    Nov 19, 2005
    #6
    I think you mis-understood my second question, in part due to me getting some numbers wrong.

    I didn't mean 2700 - the question I was asking in the second post was whether a faster DDR2 module would work in a slower DDR2 slot. I was just wondering about different speeds while both were ddr2. I guess I should have said ddr2 4200 and ddr2 5300.

    Thank you for the info though I appreciate it.
     
  7. rogersmj macrumors 68020

    rogersmj

    Joined:
    Sep 10, 2006
    Location:
    Indianapolis, IN
    #7
    Yes, that will work.
     

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