3GB vs 4GB of RAM

Discussion in 'MacBook Pro' started by mossme89, Dec 4, 2010.

  1. mossme89 macrumors 6502

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    Jul 2, 2009
    #1
    In my 2008 uni MBP, i currently have 2GB of RAM. Decent, but if i have iTunes, Word, and several Chrome windows up, it starts to beachball and really slow down. I'm not even sure if I'm using up all the RAM, it just starts to get laggy. My friend's MBP has the same 2.4Ghz C2D processor but with 4GB of RAM. Man, he can have a ton of apps open and not run into issues. I've re-formatted many different times and still have the same thing.

    I have a 2GB stick on the way, which would give me 3GB of RAM. There was a test a while back that found 3GB didn't offer much different to 4GB (LINK) of RAM. But i believe the tests were done on Tiger & Leopard, which only used 3.3GB. My question is, is there that much of a difference with 3GB (1 X 2GB, 1 X 1GB) and 4GB (2 X 2GB)? Obviously the 4GB will be snappier, but by how much?
     
  2. Hellhammer Moderator

    Hellhammer

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    #2
    Well, try with the 3GB first. If you still get a lot page outs, then you should get more.
     
  3. mrsir2009 macrumors 604

    mrsir2009

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    #3
    It will increase performance by 50%. Do you feel a 50% increase is enough, or do you need double the performance?
     
  4. mossme89 thread starter macrumors 6502

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    Jul 2, 2009
    #4
    Do you know what I'm talking about? It's not like all the RAM is used, it just starts to really slow down once i start having several things open.

    Theoretically. But what about the fact it's a 2GB stick & a 1GB stick? Would that make things less than 50% because RAM works best in pairs?
     
  5. alphaod macrumors Core

    alphaod

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    Feb 9, 2008
    Location:
    NYC
    #5
    The 1GB stick will work in dual channel with 1GB of the 2GB stick. Then the remaining 1GB on the 2GB stick will operate in single channel.

    FYI, this is called Intel Flex Mode.
     
  6. Hellhammer Moderator

    Hellhammer

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    #6
    Have you even looked at your page outs? You may have some free RAM left but page outs are what you should be looking at as they tell you do you have enough RAM (when running out of RAM, data is moved to HD which causes the slow down). If you don't have much page outs but it's still slow, then it's likely something else, maybe HD.

    Matched pairs enable dual-channeling but it doesn't really do anything in basic usage. More RAM is always better than dual-channel.
     
  7. RKpro macrumors 6502

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    Oct 27, 2008
    #7
    DDR3 1066 has something like ~8.5GB/s per channel. If you're using unmatched pairs you're losing dual channel.
     
  8. mossme89 thread starter macrumors 6502

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    Jul 2, 2009
    #8
    I'm a bit confused as to what page outs are, and how i look at them. Could you explain it to me, and what do i need to do?

    I have no doubt part of the issue is the hard drive. My last hard drive (Apple's) was failing already before it died when something hit it. Now, i'm using a replacement drive temporarily that is dying and beachballs constantly. Should replace it tonight (Hanukkah). I ordered a WD Scoprio as a replacement (link) But even before then, when my drive was healthy, it would beachball much more than my friends MBP with 4GB (for obvious reasons), and just be so much less snappier.

    A big issue is iMovie. Can't have anything else up with iMovie, just gets too slow. And often when using the preview windows and dragging the little play line across, it gets laggy and beachballs. Friend has no issue.
     
  9. daneoni macrumors G4

    daneoni

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    Mar 24, 2006
    #9
    Am i the only one who thinks you may have iffy memory installed or there's something off with the spinning up/down of your HDD?
     
  10. Hellhammer Moderator

    Hellhammer

    Staff Member

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    #10
    You can see page outs in Activity Monitor under System memory tab. No doubt the extra GB of RAM will help as iMovie is pretty RAM hungry thus 4GB wouldn't hurt. Try with the 3GB first, maybe that will be sufficient. Keep your eye on page outs so if you're getting a lot of them, then investing on some extra RAM should be worth it.
     
  11. mossme89 thread starter macrumors 6502

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    Jul 2, 2009
    #11
    Thanks, i just checked and saw 204KB, which i guess isn't much. Here's all the info

    VM Size: 117-119GB (fluctuating)
    Page ins: 1.48GB
    Page outs: 204KB
    Swap Used: 3.3MB

    Free: 339.5MB
    Wired: 451.9MB
    Active: 895.7MB
    Inactive: 362.3MB
    ^^ All fluctuating
    Used: 1.67GB

    Applications using the most RAM:
    Preview 114.4MB
    iTunes 112.2MB
    Google Chrome 107.6MB
    Finder 82.6MB
    Google Chrome Renderer 59.2MB
     
  12. Hellhammer Moderator

    Hellhammer

    Staff Member

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    #12
    Yeah, that's not that much. Have you ran iMovie since the last startup? If you're doing something RAM intensive, then you should get more page outs and thus more RAM should help.
     
  13. Stvwndr219 macrumors 6502

    Joined:
    Jan 26, 2009
    #13
    I'm sure the hard drive is the bigger contributing factor. I had lots of beachball issues with the 250GB 5400RPM drive, switched to a 7200RPM 500GB hard drive, everything sped way up and there was no problem with it.
     

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