macbook + 20" ACD

Discussion in 'Buying Tips and Advice' started by i0Nic, Aug 16, 2006.

  1. i0Nic macrumors 65816

    May 17, 2006
    Sydney, Australia
    Hey guys, I'm using a 20" cinema display with my macbook 2.0ghz. I'm noticing that things like expose are a slightly jittery at times and not as smooth as they are on the macbook without it being plugged in to the display.
    The macbook is in lid closed mode, however when the lid is open and used in extended desktop mode it's a lot more jittery/laggy.

    The laptop has 1gb of RAM, would upgrading to 2gb improve this a great deal?

    Also, the laptop gets a lot hotter when used with the display.
  2. Phatpat macrumors 6502a


    Jun 15, 2003
    Cambridge, MA
    I could understand why that happens, as the computer has to output a lot more pixels, but unless you are doing something graphically intensive I feel like it shouldn't cause it to feel laggy.

    Are other people having similar problems? This is something I would like to do with my Macbook, and I would expect better performance. So far I've been very happy with the integrated graphics.
  3. 7on macrumors 601


    Nov 9, 2003
    Dress Rosa
    prolly not.

    Multiple Displays require more video Ram to be fluid. And the Macbook is virtually locked to 64MB regardless of the amount of RAM in your book. My Radeon 9000 w/ 64MB in my old G4 didn't perform spectacularly either with a 20".
  4. Caitlyn macrumors 6502a

    Jun 30, 2005
    Applications take up RAM and so does running a second, external display. Being that the graphics card in the MacBook is itegrated, upping to 2GB may help you because your apps will have more RAM to run off of while the display gets all the RAM it needs to run. If it's the applications that are jumpy, that will help. However, if it's just on the display that things are jumpy and not the MacBook's 13 inches, then it might be a bad display or connection..?
  5. i0Nic thread starter macrumors 65816

    May 17, 2006
    Sydney, Australia
    Well it's not really apps that are jumpy. Even with just one or two low resource aps running, dashboard and expose are definately not as smooth as they should be.

    I've just done a little test with the display in extended desktop mode, and I can see that on the display that things get jittery while they're less jittery so on the macbooks screen.

    Could it really be a bad display or connections? Or is it slighty more jumpy due to being a larger screen.

    It only gets jumpy when the GPU is used such as dashboard or when theres a few windows/apps open with expose.
  6. Scottyk9 macrumors 6502a

    Jun 18, 2004
    The VRAM is now split between your macbook and the display. I noted this on my older powerbook - instead of having 64MB of VRAM on one display, you had 32MB for each, resulting in choppiness when the GPU is stressed. (now that I have a 256MB card, there is lots of VRAM to go around).

    If the GPU was apportioned according to the number of pixels, I suspect what you see on your 13" screen and 20" screen would be the same, but your 13" screen is getting a disproportionate amount of VRAM. Still may mean that you might not have enough VRAM for everything to be smooth.

    I don't think you have a lot of options - not sure if more RAM will allow more VRAM to use. Check your system profiler to see the amount of VRAM and how it is being used. I lived with it, as while the eye candy wasn't as smooth, it didn't seem to slow things down too much overall.

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