MacBook Pro Clamshell Bug

Discussion in 'MacBook Pro' started by shadowrocker05, Jun 17, 2012.

  1. shadowrocker05, Jun 17, 2012
    Last edited: Jun 17, 2012

    shadowrocker05 macrumors newbie

    Jul 12, 2008
    I purchased a 13" Macbook Pro in late 2010 and absolutely love it. However I recently purchased an external display (23" AOC IPS display) since I plan on setting up an office in my house. When the displayed arrived and I hooked it up I noticed that my internet speeds were running extremely slow on the Macbook. Using internet speed test I could tell I was getting in the range of 2 - 4Mbps whereas on my iPhone 4S on the same network I was getting in the ballpark of 14-16Mbps. I read through a lot of online commentary on here and other places of people who had issues with slow WiFi connection after installing OS X Lion however none of the fixes seemed to work for me. As a software engineer myself, I decided to run through some tests and discovered a major bug when the Macbook Pro was operating in clamshell mode. Here are the tests I performed and the results

    1. Boot up Macbook Pro without external display connected.
    2. Log on to
    3. Run test

    Results: 14.44Mbps download speeds & 25ms ping

    4. Connect external display by plugging the mini display port to HDMI cable into the mini display port on the Macbook Pro
    5. Run another test with

    Results: 14.44Mbps download & 25ms ping

    6. Close the Macbook pro and wait for the display to refresh it self (the unit is now in Clamshell mode)
    7. Run the speed test again

    Results: 6Mbps download & 35ms ping

    8. Open the Macbook Pro lid and wait for the displays to refresh themselves (the unit is no longer in Clamshell mode)
    9. Run the speed test one more time

    Results: 16Mbps download & 25ms ping

    As you can see there is clearly a problem with the wireless transmission when the unit is in Clamshell mode. I have repeated this test several times now and the internet speeds when the unit is operating in clamshell mode are always less then half and or even 1/4th of the speed when the unit is not in clamshell mode.

    Has anyone else encountered this? I have filed a bug with Apple and will post an update if I hear back.

    Update: Here is a video showing what i'm talking about.
  2. borisiii macrumors 6502

    Jul 4, 2010
    The wifi antenna cables run around the display. When the laptop is in clamshell mode you tend to get worse wifi reception, resulting in the reduced download speeds you are seeing. You also get higher temperatures in clamshell mode, so there is little reason not to use both displays.
  3. shadowrocker05 thread starter macrumors newbie

    Jul 12, 2008
    That's a pretty bad design flaw. The new Macbook Pro with retina display has the side vents so that might solve the heat buildup you are talking about but it seems like it wouldn't be that hard to engineer a solution to the Wifi problem. I'm glad to see i'm not the only one who has seen this though.
  4. samac92 macrumors 6502a

    Feb 18, 2008

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