Mid-2012 MBP, Forced to Ditch My External Monitor

Discussion in 'MacBook Pro' started by Aodhan, Jul 6, 2012.

  1. Aodhan, Jul 6, 2012
    Last edited: Jul 6, 2012

    Aodhan macrumors regular

    Jun 16, 2012
    I have been using a Dell 23-inch monitor since I got my MBP about ten days ago, and I finally packed it away in the closet because it seemed to be causing more problems than it was solving.

    I was connecting the monitor to my MBP via a DVI to MDP cable, and I did not observe any performance issues in normal use, even when playing Diablo 3 at 1920x1080. What I did notice seemed unrelated, but in retrospect, probably was.

    I was using an Apple wireless keyboard and a Logitech Performance MX mouse along with the external monitor, and found I was experiencing significant lag with the keyboard, where entire sentences would be delayed, and in some cases letters were skipped entirely. With the mouse, I experienced significant stuttering, particularly while gaming. I switched to the Magic Mouse, it was even worse.

    The list of things I tried to resolve the issue is very long, derived mostly from Apple Discussions. Remove and re-add bluetooth devices, set them as favorites, delete prefs, change speed, install Magic Prefs, PRAM/SMC, etc... Nothing worked, so I disconnected the monitor, and all my issues disappeared. Is there some undocumented problem with external monitors and Apple wireless keyboards and Magic Mice?

    TLDR: External monitor + Apple wireless keyboard and Magic Mouse = lag. Did I miss a simple fix?
  2. phyrexia macrumors 6502a

    Sep 3, 2010
    Are you using wifi while you're using the wireless accessories? I've never had any problems related to my external displays, but I did have problems similar to what you're describing when I tried to use 2.4ghz wifi and my Magic Trackpad at the same time. It didn't happen in SL, only in Lion. I either used 5ghz wireless or an ethernet connection.
  3. Aodhan thread starter macrumors regular

    Jun 16, 2012
    Definitely using wifi. I tried changing it to 5ghz as well, unfortunately that did not work. The stuttering and lagging disappears as soon as I disconnect the external monitor. I can use the Magic Mouse without any trouble if I am using the MBP's display.

    I also tried plugging the monitor directly into the wall, isolating it from the power strip the computer is on. I just don't get it. Thanks for the suggestion though! I wish that had done the trick.
  4. calvol macrumors 6502a

    Feb 3, 2011
    You know what, I worked in the PC industry for a chip supplier, and when PCIE first came out, the PC OEMs had a hell of a time shielding the PCIE bus internally in the laptops, because it was causing interference to the upper channels of the WiFi band. This is one of my fears of extending the PCIE bus through a Thunderbolt cable, in effect, an antenna is created, causing enough interference to block WiFi/Bluetooth channels. I'm not in the industry anymore, but I would bet this is what's happening. I'm going to try to read up on it....
  5. brand macrumors 601


    Oct 3, 2006
    Your antenna/interference issue will be moot when fiber optic ThunderBolt cables are released. I wonder if the extra circuitry and micro-controller in the coper ThunderBolt cable would prevent or reduced the interference that you are concerned about.
  6. gpzjock macrumors 6502a

    May 4, 2009
    Way back in 2005 I bought a G5 2Ghz iMac with wireless mouse & keyboard. It suffered horrendous lag on both typing and movement periodically without an external monitor. I binned the wireless and used USB mice & keyboards ever since. Never had a problem with wired kit and the mice are much lighter to use due to no batteries. Also as an avid WoW player having the batteries die in the middle of a 25 man raid was very annoying. Wires are good.
  7. lannisters4life macrumors 6502

    May 14, 2012
    Wow, this is interesting. I have been experiencing strange mouse lag in bootcamped Windows 7, whenever more than one finger is on the magic mouse, there would be huge lag across the screen. I have a Macbook Air and Thunderbolt display. Weirdly this doesn't seem to happen in OS X, so I had thought it was some kind of crappy bluetooth driver. But just now I unplugged my screen and used the magic mouse in Windows 7, and there's no lag to speak of. How crazy.
  8. Dangerous Theory macrumors 68000

    Jul 28, 2011
    Did you try to separate the MacBook & mouse from the monitor as much as possible? If it is interference, then you may be able to move outside its range. Does sound very unlikely though. More like a conflict within the OS.
  9. Aodhan thread starter macrumors regular

    Jun 16, 2012
    The MBP is in a BookArc at the far end of my desk, so there is about a foot and a half between it and the monitor, keyboard and mouse. My desk is very shallow though, there is no way to put more distance between the monitor, keyboard and mouse.

    My last hope at this point seems to be Mountain Lion. When it comes out, I will do a clean install and hope for the best. I would do a clean reinstall right now but I received no installation media and I don't feel like waiting for 5GB to download with internet recovery. I can't use Time Machine because it wouldn't be a clean install.

    I would not be surprised if it was some sort of interference, as calvol suggested. In which case there may be no solution.
  10. Freyqq macrumors 601

    Dec 13, 2004
    If it really is a signal issue, move the USB receiver for the kb/mouse to a better location. I use external monitors with my mac and don't have any issues with my logitech wireless kb/mouse.
  11. Aodhan thread starter macrumors regular

    Jun 16, 2012
    It is possible that I have resolved this issue, by doing something that seemed pretty counterintuitive. I moved my MBP closer to my keyboard and mouse. So far, for the last couple hours, I have had no stuttering or lagging, where before I could barely go a few seconds without problems. Perhaps having the lid closed is interfering with the the bluetooth antenna? Either way, moving it much closer (within about 10 inches) seems to have resolved the issue. Keeping my fingers crossed.
  12. eagandale4114 macrumors 65816


    May 20, 2011

    Use GFX CardStatus and force the system to use the nvida gpu.

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