Two different size/brand RAM for Macbook Pro Help pls!

Discussion in 'MacBook Pro' started by atisz, Oct 28, 2011.

  1. atisz macrumors newbie

    Joined:
    Apr 8, 2010
    #1
    I have a MBP Santa Rosa, I decided to upgrade the RAM from 2GB to 6GB. So I need a 2GB and a 4GB memory card. I barely find 4GB RAM in my country which is not in a kit. There is a large selection for the 2GB though.
    The best option looks like would be a Corsair 4096MB 800MHz CL5 DDR2 - VS4GSDS800D2
    and a GeIL USA 2048MB 800MHz CL5 DDR2 - GX2S6400-2GB
    I know my laptop only works on 667Mhz, and these would work only on 667Mhz, but I couldn't find any 667Mhz 4GB memory card, and the 800Mhz ones usually cheaper.
    Would these two work together?
    Both CL5 (I'm not sure what it means), but the Corsair is 6-6-6-18 and the Geil is 5-5-5-15
    Is that a problem? Please let me know what are the most important specs they have to match.
     
  2. mape2k, Oct 28, 2011
    Last edited: Oct 28, 2011

    mape2k macrumors regular

    Joined:
    Apr 18, 2011
    Location:
    Germany
    #2
    First of all, why would you want 6GB if it's such a hassle? Why not buy a cheap 8GB kit an be done with it?

    On your question: The CL values give you the timing of your RAM. Usually, the manufactures provide the fastest CL times that their RAM is supporting. In your case, the Corsair is slower than the GeIL one.
    Both RAM channels have to run at the same latency. This means the GeIL would need to "slow down" for the Corsair. If that really works, I really don't know!

    My advice: Just buy a 8GB RAM kit 667MHz. That way, you will know for sure that it works. Your proposed setup of 2GB and 4GB with different latencies is a bit of a gamble...

    Edit: Just read a little more. Which model do you have, when was it manufactured? This model seems to be the first one supporting 8GB.
    Source
     
  3. ct2k7 macrumors 603

    ct2k7

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    Aug 29, 2008
    Location:
    London or Florida
    #3
    I am yet to find someone who cares about CAS Latency.
     
  4. mape2k macrumors regular

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    Apr 18, 2011
    Location:
    Germany
    #4
    ? Once you over clock a CPU without free multiplication, you really start caring about the CL values ;)

    But you are right, that's not the majority of users. Still, I wouldn't hope on the auto-detection getting the timings right if there are two different RAM sticks in the slots.
     
  5. ct2k7 macrumors 603

    ct2k7

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    #5

    In laptops/notebooks anyway :eek:
     
  6. atisz thread starter macrumors newbie

    Joined:
    Apr 8, 2010
    #6
    Thanks for the reply. The reason I want 6 GB is that I have the June 2007 Santa Rosa model which allegedly can work safely with maximum of 6 GB RAM.
    http://forums.macrumors.com/showthread.php?t=573906
     
  7. mape2k macrumors regular

    Joined:
    Apr 18, 2011
    Location:
    Germany
    #7
    Well in that case, I'd suggest you look at least for RAM of the same manufacturer and the same latencies. Then you are on the safe site regarding compatibility.

    If you don't find single sticks of RAM, you might want to look for kits. Those are sometimes even cheaper than single sticks and are more readily available. You could always sell the extra stick or keep it as backup. What is your budget?
     
  8. atisz thread starter macrumors newbie

    Joined:
    Apr 8, 2010
    #8
    I decided to order it from the US. On Newegg, they sell the 4 GB stick for $45-70, in my local stores it costs about a $100. And I don't have to worry about the shipping, because my brother goes to the US in about a week.
    Those memories tested by many MBP users, so there should be no problem.
     
  9. itegypt macrumors 6502

    itegypt

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    US/Q8
  10. mape2k macrumors regular

    Joined:
    Apr 18, 2011
    Location:
    Germany
    #10
    For a 2007 Santa Rosa MBP?!
     
  11. atisz thread starter macrumors newbie

    Joined:
    Apr 8, 2010
    #11
    Certainly not, that's a ddr3, my model works with ddr2 667 mhz. I wonder why is the ddr2 much more expensive?
     
  12. nebo1ss macrumors 68030

    Joined:
    Jun 2, 2010
    #12
    When you make and sell less of a product it gets more expensive. There is more demand for the newer memory.
     

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