Lion graphics extremely slow with Radeon HD 2600 Pro 256MB

If you have used the kexthelper provided on the fix, it have created a folder under /Backup with the original kext... just repeat the proccess using the original ones.

As Mike.bar says, use the kexts on the backup directory.

Anyways, it´s strange to get a kernel panic using ONLY those 3 files (if you add, for example, the ATIRadeonX2000.kext you get a nice kernel panic).

What iMac do you have? 7.1, 8.1... 2600pro or other ATI VGA, version of OSX... more info please.

Remember, if you upgrade your system to the next version of Lion, it probably will delete this files and put new ones (and the problems MAY return). Then you´ll have to reaply the patch. But, I only know that it doesnt cause problems on 10.7, 10.7.1 or 10.7.2 . Who knows what can happen on future versiones (kernel panics!).

Thank so much for posting the Snow Leopard drivers and providing instructions on how to load them! My iMac is happy again!!! It's still unacceptable that Apple did not address this in 10.7.2 since all they had to do is replace the drivers.

You´re right. It´s disappointing to see this failure on every version of Lion... 😟

I couldn't revert back to the original files because I couldn't boot OS X at all. It would crash as it was preparing to go to the log in screen. I had to go to the recovery HD and reinstall Lion 😟

I have applied the patch to my iMac with ATI Radeon HD 2400 and everything is smooth again. Thanks! A lot actually. Replacing the drivers felt a bit risky but up until now I did not notice any side effects.

In OpenGL Extensions Viewer I have performed the performance tests for the core profile. Only the 3.1 and 3.2 tests passed (which is also the case for the original Lion drivers). The overview shows that up to version 3.2, 100% of the features is supported. Higher version are only partly or not supported. Also note that the framerate reported by the performance tests is much higher with the SL drivers compared to the original Lion driver (260 vs. 60 FPS).

Either this problem has no priority at Apple or it is a very hard to solve problem, otherwise they would have fixed it in 10.7.2. Hopefully they do in the next update. At least with this patch I am happy for now.

Hi Harkaits, will it work for Ati HD 4670 as well?

My iMac is animations and transitions are choppy and not smooth at all...

I only tested it on radeon 2400 and 2600... dont know if it works for 4xxx models, but I added the file for those who want a to try...

If you try it, please post results!

Well, I don't know... what do I risk to brick my system?

Yes, If it goes wrong, you can get a kernel panic and have to reinstall the OSX.

If you have an USB hard drive or a 16GB pendrive you can make a fresh install on it of Lion, boot it, and then try. If it works, then you can try on your system without risk.

I see in the package you have posted there are other kexts, and a ATI4600Controller.kext too;

I should install that one for my hd 4670, right?

in you case, this are the files:

ATI4600Controller.kext

ATIFramebuffer.kext

ATISupport.kext

Ok, installed on my usb disk and, actually, it works much better.

Thank you very much Harkaits;

but before I do it on my primary disk: will this hack remain at every osx update? Or will I have to do it again?

Besides the obvious pros are there maybe any cons we could experience using this old kexts later on?