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

Any news?

Just read 2 posts before yours...

I did... just wondering if there was any more confirmation! Thanks!

Sounds reasonable. Any hope I had that Mountain Lion would have stalked and eaten this problem were quickly quashed after unleashing it. My iMac had enjoyed several crash/freeze-free weeks after applying the kext fix; they returned within 20 minutes. But I reapplied the fix and it still works... so far.

It took about 24 hours, but I just had my first freeze on Mountain Lion. Back to the 10.6.2. kext files... will Apple ever fix this?!

For me it just works without kext fix, but I make clean install... But system runs faster on my Mac than Lion

Krzysiu -- we're going to be watching your experience with Mountain Lion, since you're the godfather of the kext fix. Please let us know in the next couple of weeks if your iMac ever freezes. I can't imagine why a clean install would make a difference. But if it does, then I'm happy to do it. Thanks for your help so far. -- Tony

Just wanted to add my voice to this discussion topic. Very much appreciate the fix with the kext files. Have used it for several months now on my wife's iMac, after months of frustration searching for the answer.

Have installed Mountain Lion on my new Mini :-) but will try it on the iMac this weekend and will advise if freezing returns.

Update: It ran for a day and then crashing returned. Going back to the Kext from 10.6. So Mountain Lion does not have a fix either.

Note: I did NOT do a clean install though. I just ran the updater.

@aieronimo -- I'm believe that the freeze reason in 50% it is Adobe Flash. In my case screen freezes when I was watching YouTube movie or when browser displaying big flash ad (of course not with 10.6.2 kext's). Now I have 10.8 system and the newest flash player. That's why I made clean install

Krzysiu - In your experience, with a clean install of Mountain Lion (and no kext fix), are you still getting screen freezes if you run Adobe Flash? Or are you not having any crashes at all with a clean install (and no kext fix)?

I don’t believe that the freeze is caused by Adobe Flash. Flash has always been an application that caused macs to crash, Steve Jobs stated this in his article where he explained reasons for not running flash on iphones a couple of years ago.

It has something to do with apps that pull on GPU. For example some tools in Photoshop cs4 and cs5.

And the Sleep function. When I stopped my imac from entering sleep with “caffeine” I managed to control the crashes , freezes and pixel artifacts, they started happening from 9 in 9 days, it is quite weird...but I deal with very small files.

I guess the freezes also depend on how and for what we are using our computers.

But a radical clean install helped me a lot and running repair permissions periodically with other tools besides disk utility as well.

no.

there is difference between clean install and upgrade. kext caches are rebuilt anyway.

if you do some sort of gpu intensive stuff, your gpu will bite the dust. could be some sort

of manufacturing problem with a series of GPUs located in our imacs, and there was a

workaround in the pre 10.6.3 drivers.

they've introduced opengl3 support in 10.6.3, as seen here http://netkas.org/?p=362

probably this is where the root of the issue is. according to my theory, if we could disable it (opengl3) won't have no freezes afterwards...

(my imac7.1 has ML with 10.6.2 ati drivers.)

I just installed this tool („OpenGL Extensions Viewer“), as it is available or free in the Mac App Store. It shows me exactly the same output as shown in that screenshot you linked to (95 % or 22/23 of OpenGL 3.0, etc.). My iMac is running the 10.6.2 kexts on OS X 10.6.8.

strange. i did the tests, basically all opengl3.0 tests fail on the 10.6.2 drivers.

i spotted some diffs.

the "extensions" tab shows alltogether 133 extensions, however the "database" tab says, there are

137 extensions supported on macos with ATI HD2400.

for example extension "container object shareable" is missing on my system.

3 less ARB extensions (53 in database vs 50 in extensions) - sorry was to lazy to check which one is missing.

it would be nice to run the tests on 10.8 drivers on the same hw. i will give it a try and post what i've found.