Question about RAM, max and type.

Discussion in 'MacBook Pro' started by lordthistle, Sep 4, 2008.

  1. lordthistle macrumors 6502

    Feb 29, 2008
    Hello, I need your help.

    If you go on the apple online store and decide to purchase a MBP, you can choose to add more memory. Basically you can have 4GB instead of 2GB.

    Anyway, please read this (dated August 14, 2008):

    in particular the Note.

    Which macbook pro are they speaking about? Previous one? Current one? Next one? Ancient ones?

    With 2x2GB modules, how much memory will be used? 4? 3? The note says only 3, when they sell it they do not say anything about it. Wasn't Leopard's kernel to address 4GB? Wasn't Santa Rosa? What?!?

    Furthermore, reading here and there, I found a lot of warnings about memory that can be mounted on a mac. For example, Kingston has "special" ram modules for mac. A lot of people said that the Kingston value ram wouldn't be good enough for our mighty notebooks.

    Anyway, there are a lot of rams respecting all of the criteria listed by apple in the page linked above. Why shouln't they be good enough?

    What a mess.

  2. Cave Man macrumors 604

    Cave Man

    That article applies to the Calistoga-based C2D MB/MBP, not the current SR MB/MBP. They take 4 gigs, and probably 8.
  3. GGJstudios macrumors Westmere


    May 16, 2008
    The maximum useable RAM for current MacBook Pros is 4GB. The link you provided is for an older model.

    You'll find answers to this and many other commonly asked questions under the Guides tab at the top of this page:
    If you have questions that these sources doesn't cover, you can check to see if it has been answered in another thread by doing a Google search of the forums. I hope this helps!

    For information regarding various Mac models, including maximum RAM, use MacTracker.
  4. lordthistle thread starter macrumors 6502

    Feb 29, 2008
    I had already read the guides but they do not contain an answer to my question. And obviously I searched this forum. Anyway, thanks for the advice.

    The document I linked has been published/modified on August 14, 2008. "Macbook pro" is not restricted to previous models. As you can read, the OS says there are 4GB, but addresses 3.

    The guides say that some Kingston are not guaranteed to work on macs (which I already knew). I cannot understand why, since they respect the specs listed on the apple site. Either the Kingston value rams do not respect the specs or the specs listed on the apple site are wrong.

  5. Cave Man macrumors 604

    Cave Man

    The Calistoga memory controller is 32 bit, thus you would only have access to about 3.2 gb of RAM if you have two 2 gb sticks in it. The first generation of this chipset (used on Core Solo/Core Duo MB, MBP, iMacs and Minis) could only take 2 gb of RAM because of an EFI (firmware) limit placed upon it by Apple. The Mini is still based on Calistoga and although Apple says it can only take 2 gb of RAM, it can take 4 gb of physical memory but address only 3.1 gb of it. (This is the same reason why the SR MB/MBP/iMac can probably takes 8 gigs of memory since SR can address it, although virtualization is apparently screwed.)

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