Stupid RAM questions.

Discussion in 'MacBook Pro' started by mcdj, Jan 7, 2011.

  1. mcdj macrumors 604

    mcdj

    Joined:
    Jul 10, 2007
    Location:
    NYC
    #1
    I recently bought 2x4gb Samsung RAM sticks for my late 2009 MBP 13" on ebay. The auction description said it was 1066MHz.

    Installed the RAM, seems to work fine. Not really noticing a major difference between the new 8GB and the previous 4GB.

    However, system profiler shows it as running at 1333MHz.

    I googled a bit and people seem to be obsessed with cl9 vs cl7, whatever that is.

    The questions are, is my RAM actually running at 1333MHz? Most people say it gets downclocked to 1066 in a MBP. Wouldn't the system profiler indicate the actual speed? And how can I tell if my RAM is cl9 or cl7? Finally, if it is cl9 and if the system profiler is wrong and I'm actually running at 1066, is there any performace hit with using the incorrect RAM?

    Gracias.

    mcdj
     
  2. mcdj thread starter macrumors 604

    mcdj

    Joined:
    Jul 10, 2007
    Location:
    NYC
    #3
  3. tasslehawf macrumors 6502

    Joined:
    Jun 13, 2003
    Location:
    Austin, TX
    #4
    You can always use faster ram, it will just run at the slower speed.
     
  4. vant, Jan 8, 2011
    Last edited by a moderator: Jan 8, 2011

    vant macrumors 65816

    Joined:
    Jul 1, 2009
    #5
    CL7 is used by Apple for this round of laptops. If you computer turns on and runs stable, you are fine.

    Also, your ram IS running DDR3 1333. It can take higher speeds provided the CL is 7.

    Not always.
     
  5. mcdj thread starter macrumors 604

    mcdj

    Joined:
    Jul 10, 2007
    Location:
    NYC
    #6

    Interesting. Thanks for the info. I'm still curious about how/where I see whether I have cl7 or cl9. It's not written on the chip that I can see, and system profiler doesn't specify.
     
  6. NickZac macrumors 68000

    NickZac

    Joined:
    Dec 11, 2010
    #7
    This is an interesting subject which seems to have, as you noted, two sides clash. I have read that higher speed RAM will generally run at the native speed.


    http://www.tomshardware.com/reviews/ram-speed-tests,1807-15.html
    It is a little bit older but I am a pretty big fan of reading their information. It may not apply today as the iX series and obviously the coming Sandy Bridge are not tested or discussed (they didn't exist then), so it is more of a basis than a solid conclusion.





    Crucial, one of the memory experts for Macs, states that for the 2.53 13 inch MBP, the upgraded RAM have these specs:
    I would dare theorize that if there was a benefit to a different speed RAM, that Crucial would be recommending and selling that as opposed to the 8500
     

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