- Jul 8, 2012
- Intel DH55TC
- Intel Core i7-870
- Gigabyte 550ti OC
- Classic Mac
- Mobile Phone
Mobile GPUs usually have different memory controllers to conserve power, as I have not had any channel exceptions, or freezes for that matter, with my 550ti for the past few days.10.8.2 is better but they still occur. I believe it is a memory leak in the GPU usage - I can monitor mine using an application I run 24x7 (BOINC from BERKLEY) and it uses Open CL for GPU*processes. When I boot it reports 905M free on my GT 550M; after overnight running, screen saver comes in once and then the display sleeps for 8 hours, that number drops to 840M or so. This continues throughout the day until the memory drops so low I'll get messages (internal to BOINC) about how the process is waiting for GPU memory. If I do not reboot, it will eventually freeze trying to come out of a screen saver or back from display sleep with the Channel Timeout message.
My son's MacBookPro has a similar issue although his reboots after the error, not a freeze; my wife's MacBookPro freezes. My daughter's MacBook has not failed, as far as I know, and she NEVER reboots. My MacMini Server has freezes but they are really rare.
The point is these issues will eventually be addressed and are not unique to the 550TI; turning off the cutesy stuff like background changes will reduce the affect and rebooting once a day may 'eliminate' it for most of us altogether.
vczilla's fix works; I did it wrong before he posted his fix and had issues so if some of you are having issues, just clean it up and try again; ignore the error messages on commands until the CHOWN command - if CHOWN doesn't find something then you did something wrong.