Mac Pro lags since I connected a 2nd monitor - HELP!!

Discussion in 'Mac Pro' started by RickUnique, Feb 28, 2010.

  1. RickUnique macrumors newbie

    Feb 28, 2010
    Hey guys,

    I just bought a 2nd monitor and i have lags every 5 seconds which
    last about half a second (feels like 10 or less fps during the lag).
    It happens with all kinds of applications. It gets worse with multiple
    applications openend at a time. The crazy thing is that it only occurs
    when i start to use both monitors at the same time. When i e.g. use
    Logic 9.1 and use one monitor everything runs nice and smoothely
    but as soon as i move the window slowly to the 2nd monitor i can
    see the window lagging while I'm moving it. This is really annoying
    because it seems not every input from the mouse/keyboard gets
    into the system and its not a smooth workflow at all.
    I switched the monitors connections but it didn't help.

    Mac Pro (Early 2008) 2.8Ghz 8-core
    Snow Leopoard ( 10.6.2 )
    6GB RAM (2x2gb kingston, and the usual 2x1gb)
    ATI 2600XT and 3 HDD.
    1 Monitor 24" running at 1920 x 1200
    1 Monitor 22" running at 1680 x 1050

    I really hope that you guys can help me out with this one.
    What coule be the problem? The ATI 2600XT should definately
    be able to handle two screens at one with such little graphics
    in logic 9 ?!

    I want to run Logic 9 and an analyzer software (spectre from AE)
    at the same time but its not possible with the LAG.

    The problem/lags also occur when i sync the monitors.

    Could the RAMs be a problem ?
    Would a 2nd graphics card be a solution? But as I said
    before its not a graphics demanding application.
    Is it a hardware or software "error"?

    - The whole System lags (not just one monitor) when
    I start to use both monitors (having application windows on both).

    Thank you in advance for your help guys!

  2. ljonesj macrumors 6502a


    Oct 20, 2009
    Kingsport TN
    i dont know if this will help but try it run both moniters with the same resolution like 800x600 on both for example that may help and make sure both have the same refresh rate on both
  3. kellen macrumors 68020


    Aug 11, 2006
    Seattle, WA
    Something sounds off, I ran dual 23" with the 2600 for some time, both at 1920x1200.
  4. RickUnique thread starter macrumors newbie

    Feb 28, 2010
    Hey guys !

    Thanks for your Tips.
    Unfortunately I was'nt able to fix.


    I tried running both monitors with a resolution of 1024 x 8xx but it didn't
    change things - maybe it was a tiny little bit better than with the standard
    resolution. Both have a refresh rate of 60Hz. One Monitor says "60Hz(NTSC)"
    and the other just "60Hz" but that should be the same.


    What kind of applications are you runnin
    Anyone else any recommendations ? Is my only chance buying a new graphics
    card like the ATI 4870 ? damn 3xx is quite a price for running a 2nd monitor
    while already having 2 DVI connections.

    Even with the safari window I get some lags while I am moving it in from one
    monitor to the other. It is just noticeable - not as bad as with the Logic Pro
    window or some other """"graphics demanding""" application.
    I am - lets say a little bit - "addicted" to a smooth workflow and I even feel
    very little lags on the system.

    Hope somebody enlightens me or my mac pro with some good advice !


Share This Page