Hello all, after a lot of time trying to hack my Acer Notebook with OS X higher then 10.7.1, i noticed that disabling BeamSync with QuartzDebug is a solution for me. It's like pressing a 'magic-button' . All … glitches, system lags, hangs, unusable mission control, main-ring-hangs in kernel.log …disappeared. OK... little tearing effect is there while moving windows very fast but it's because i disabled BeamSync . I have nothing else on the con side. I can't explain in detail why it has this effect for me but i think it skips now some not proper working 'alignment job' between display and display-driver. I guess that my laptop screen isn't compatible with the newer osx HD3000 drivers (external hdmi monitors worked fine). I also tried a lot of solutions for my Laptop before. Like GraphicGlitchFix, connector patching, creating display edid and so on. At first i used a applescript to open QuartzDebug, disable BeamSync and kill it so that the effect stays permanently - But it's ugly as hell… I found no program on the net to do it invisible. After googling a bit i found a code snippet for osx tiger opened Xcode and damned myself being such a objective-c/Xcode novice. So if you just like to try it for your machine or you need more fps in you favorite game (I read some guys have performance boost with disabled beamsync - dunno) here it is: #### BeamSyncDropper #### --- Just trying: --- 1. Go to the extracted directory with Terminal (example: 'cd /Users/Name/Desktop/BeamSyncDropper2/LionBuild') 2. chmod 775 BeamSyncDropper2 3. run with './BeamSyncDropper2' Just log off and log in to turn BeamSync on again. --- Installation: --- 1. Copy the file BeamSyncDropper2 to a location (i use '/Extra') and set permissions ('chmod 775 BeamSyncDropper2'). 2. edit the 1 row of the applescript BeamSyncDropper2Starter to your path. 3. Save the script as program (use 'save as' option). 4. Open system settings, go to user menu and add the script in the start items section. 5. Logout and login again. (If you see a apple script icon in the taskbar for <= 5 sec then it's alive!) Note: I only tested the tool on 10.7.5 and 10.8.2 enjoy! [Upd 14.03] WARNING: Tool will add key Compositor to com.apple.windowserver.plist. I can confirm this on 10.7.5 and 10.8.2. If you have trouble after using my tool please run the following command in terminal: "sudo defaults delete /Library/Preferences/com.apple.windowserver.plist Compositor" Many thanks to nyolc8! [Upd 20.09.13] v2 version released! Now with -stop -start and -force parameter to turn Beam Sync on and off directly. Post #12 !!!