Q: 24" iMac Screen Freezes since 10.6.3 update - pls help!

Andy, I'm trying this (CUDA, directly from the NVIDIA site) now.

Of everything I've been suggested to try via my own thread on the subject https://discussions.apple.com/message/21877646?ac_cid=op123456#21877646 your solution seems most likely to be the fix!!!

Fingers crossed! Thank you in advance!

Can someone repost the KEXT fix at the end of this thread? I see lots of reference to it, but I can't find the actual fix anywhere...

It was on page 90

https://dl.dropbox.com/u/90315541/Krysztof%20Turek%27s%20Fix.zip

Thanks, got it

Must've scrolled past it in my mad search!

My screen is shaking while scrolling while using safari as well as apps like google earth. This has been happening more after the last update. Apple please fix.

So it's 10.8.4 time.

Did someone install it allready? Does the kext fix still work?

GPU Debug issue solved? (Sort of... )

The problem is GPU Hardware acceleration. That's it. Most likely a problem with Apple's graphics drivers.

Here is a workaround that will work for any modern Mac and OS

If you experience these freezes when running a Mozilla browser you can turn off hardware acclelleration in Preferences / Advanced / General. Just de-select "Use hardware acceleration when available" and restart ytour browser.

Pages will load slower but the freezes *will stop*

If Aperture is the trigger, you'll have to look into turning GPU hardware acceleration off in that.

Of course this is only a workaround.

Ultimately the problem is either the grpahics cards (of which there is a very wide variety affected) or the Apple graphics firmware and/or drivers.

Please record your expereiences with this workaround below. Maybe we can build evidence of a wider issue and get some action from Apple.

Also note the steps here:

https://discussions.apple.com/thread/2384136?start=405&tstart=0

Obviously you would need to re-enable hardware acceleration in your apps to see if that works for you.

installed 10.8.4. had almost 1 day w/o freeze. then it hit me hard.

imac7,1 with HD2400, btw.

the strange stuff is however, that i managed to restore it w/o rebooting the machine.

see?

sh-3.2# w

23:41  up 1 day,  3:38, 4 users, load averages: 0.53 1.39 1.27

USER     TTY      FROM              LOGIN@  IDLE WHAT

swm      console  -                Wed20   27:31 -

swm      s000     -                Wed20   27:31 -bash

swm      s001     -                Wed20       - w

swm      s002     -                Wed23    4:44 -bash

sh-3.2# tail -2000 /var/log/system.log|grep End\

Jun  6 23:29:29 crowley kernel[0]: ** GPU Debug Info End **

Jun  6 23:29:47 crowley kernel[0]: ** GPU Debug Info End **

sh-3.2# date

Thu Jun  6 23:44:30 CEST 2013

the uptime is 1 day 3:38.

the time is 23:44 and i had the gpu crash 15 minutes ago according to the system.log.

the way i did this:

1. noticed frozen screen, just pointer moving.

2. put imac to sleep using power button (short press)

3. waited couple of minutes till the fan stopped

4. woke imac by mouseclick

5. noticed screen filled with junk, though application windows were recognizeable (at least the shapes)

6. noticed the mouse works, the computer reacts to clicks

7. clicked with mouse to one of them titlebars, dragged it around the screen, the app's window got restored to normal.

8. repeated these steps with some of the apps

9. put imac to sleep using apple menu

10. woke mac after 10 seconds using mouse

11. tada! everything is back on track except the menubar, which still had some artifacts

12. switched spaces using command+arrows to refresh menubar

13. switched back to original space, menubar is ok

bonus steps:

14. open discussions.apple.com and report the crash

15. write this post about bringing the mac back to life

i will keep on using 10.8.4 drivers, and see what comes out.

I'm starting to suspect a Canon Printer Driver update is implicated, bizarre as that may seem.

I'd like to ask when people got their first GPU freeze and what they installed shortly before that.

My first GPU freeze was on march 4 2013.

After that, a month's gap, then once or twice a week until I turned off GPU acceleration in Firefox.

No freezes now since May 17

You can find this information by opening Console (in Utilities) and looking back thoough the current and previous Kernel logs (listed under /private/var/logs which is also the location of the actual logfile). Type "GPU" in the filter box to see all the dates when it occured. Logs labllled something like "kernel.log.0.bz2" are your older log files.

Next have a look at what you might have installed on the day of your first GPU freeze or shortly before.

I installed Canon printer software update 2.11 via Software update (having put it off for ages) on 4th March - twelve hours later I experienced my first freeze

One month after that, on April 4, Canon Printer Update 2.11 was installed again via Software Update (strange, I know)... and, you guessed it: 7 hours later came my second ever freeze

Of course this could be a non-causal corellation and I can't find any correlation between subsequent GPU freezes and any patter of installer activity or Software Update. But if your expereince is similar we may be onto something here. If not, I can rule it out.

You can check all updates applied via Software Update in the relevant panel of System Preferences.

Other information can be found in Console again by looking at install.log and previous install logs.

London, eh what?

Well, the first post in this thread was from 2010. My own problems with freezes started years ago, long before that particular Canon printer driver update. OS X update 10.6.3 seems to have been the first instance, hence the kext fix back to 10.6.2 GPU drivers has been a solution. Your Canon update might have been a trigger, along with many other things, but I wouldn't say it's causal. I and many others have never installed any Canon drivers at all, I'm sure.

I've been experiencing freezing on my 2006 imac for a long time. The colours in the screen were also way off and the text becoming fragmented. Yesterday an independent Apple supporrt guy was setting upma couple of machines for me in a new office and suggested that it might be to do with the user account. He set up a new user account and it's transformed the look of the screen and also speeded to imac up considerably. I'll wait and see if & when it freezes again. The old account is still there I believe just in case I need to access some of the files.

10.8.4 does not fix the freezing problem ....

Waiting for 10.9     LOL

Thanx for your reply.

Mine

iMac 8.1

24" ati Radeon hd2600pro 256

I just installed ML Gold again and updated to 10.8.4.

Applied the kext fix on the 10.8.4 (kext helper, still hangs aftewards) and it rebooted fine and works fine.

I think Apple will bring the solution for this machine in 10.9! (not!!!!)

Has anybody tried this?

http://blog.djmnet.org/2011/02/03/snow-leopard-crashes-on-a-24-imac/

'The video chip (GPU) in mine is an ATI Radeon HD 2600 Pro. Apparently Snow Leopard drives the GPU harder than Leopard does, but runs the iMac’s fans at the same barely-audible speeds. The problem is more likely to occur on iMacs that are left on all the time, as mine is.

The solution is to install a third-party fan control program to force the fans to run faster and keep the inside of the Mac cooler. I installediMac Fan Control. The iMac’s fans are now audible, but not too objectionable, and it hasn’t crashed in the two months or so since I installed iMac Fan Control.'