Tip: Running cool while running an external monitor

Discussion in 'MacBook Air' started by hellobenny, May 12, 2008.

  1. hellobenny macrumors newbie

    Apr 26, 2008
    Hey guys, I just have a tip I'd like to share to y'all. I normally plug my mba into a dell 24" external monitor (1920x1200) at home. Whenever I do this however, the system heats it up and the fans spin up to max. Somehow the graphics processor in my mba is having a hard time driving both the internal and external displays.

    What I realized is that I don't really use the internal display when I'm connected to my 24" anyway, so if I could just disable the internal screen it would free up some needed vram and overall cool down the system. However, the hard part is that there's no obvious way to do this for any mac notebook.

    Well, I ran into this tip here that basically allows me to do exactly what I want to do:


    Basically all you have to do is close your lid, plug in the power and the external monitor adapter, then plug-in a usb peripheral (I usually plug in a usb hub when I'm sitting at my desk anyway). Plugging in the usb will wake the system. After you re-open your lid, the internal monitor will remain off. Therefore, your mba will be driving only your external monitor at this point.

    Now while running my external monitor, my mba is staying 5-10C cooler than before (around 55C cpu temp under light usage).

    So, if you are having heating issues while having an external monitor plugged in and you don't mind turning the internal off, then try this tip out!
  2. ayeying macrumors 601


    Dec 5, 2007
    Yay Area, CA
    Some like to dual screen, like me. For me I'm hooked up as dual screen. My macbook air 1280x800 with a 20" dell monitor, 1680x1050. The system is running at 40% cpu, 59 deg C, 2500rpm for the past 2 hours.
  3. richard.mac macrumors 603


    Feb 2, 2007
    51.50024, -0.12662
    i do this with my MBP by just plugging in my ACD and the power cord, close the screen and then wake it with my keyboard. this seems to shave off about 5 degrees compared to when its shut. but when you sleep it and then wake again the MBP screen turns back on. i would like to have the MBP screen off all the time like the last poster in that link.

    most of the time i want the MBP screen off becuase i dont have a stand and dual screening with the MBP is annoying; id rather have another ACD. my MBP only has 128mb of VRAM so 64MB is split between each screen and animations get choppy.
  4. poisonapple macrumors member

    May 7, 2008
    Silicon Valley
    I've found, that even with Coolbook, driving an external monitor really works up the temp. Watching video for any length of time via an external monitor is not a good thing. My MBA heats up pretty good and the fan spins up to 6200 RPM pretty quickly.

    This is with leaving the lid shut and using my mini dvi to DVI adaptor.:)

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