Lion graphics extremely slow with Radeon HD 2600 Pro 256MB

it probably don't remain, so we have to be prepared to remade the fix until apple release fixed drivers. What I do is to have a clean install on a external drive and make a image from it using disk utility. That save me to have reinstall it something goes wrong. I just need to restore the image to that partition instead reinstall (it takes me just a few minutes). Also... if you broke your main system, you can restart from it (external drive) and reapply the original lion kexts on the internal drive to restore your system.

Hi,

The way Harkaitz posted on how to fix the issue does work on my 24" iMac 2.8GHZ early 2008. Preformance difference is like day and night no joke its running smooth like snow leopard again.

This is a great temp fix but apple REALLY needs to fix this issue, I cant imagine how many people there our around that dont realize teh reason the imac is going slow is because of drivers, this looks like sloopy work and I would hate for apple to get a bad rep about this.

Thanks,

Bradley Clarke

Thank you SO much Harkaitz.. This has made such a difference..

When I checked the frame rate of no limits roller coaster simulator it was 25 - 45 fps before this fix.

Now it is 55 - 199 fps!! Fantastic :)

Thank you again..

Kevin..

Hi,

Same problem here in a early 2008 iMac with a ATI Radeon HD 2600 Pro 256 MB.

I don't understand why Apple din't fix yet the problem after 2 updates of Lion...

Sadly... after using the snow leopard kexts on lion for a while, I have been feeling the poor gpu performance again... seems it happens after using a gpu-intensive application and I have to restart my mac once again.

Same as Mike, went back to original kexts

Which kind of aplication do you use?

When I apply the fix the perfomance is ok (I dont reset my computer almost never)

Anyways, try the kexts from another version of SL. Maybe that could help!

Using the SL kexts, I now have lockups when waking from sleep if I have airport enabled. Anyone else see this issue?

I use basic applications, like safari, itunes, pages, nothing too heavy which loads enormously cpu;

I have 8gb of ram installed by the way.

Just like me, but I only have 4GB of ram...

Dont know why it works for me and not for you...

We have different cpu and different vga though; mine is a Core duo 3,06 ghz and Ati hd 4670...

Oh!, I didnt remember that you were with 4670. Anyway, you can try to use other S.L kext! 10.6.2 are too old for that vga.

I see.. ok, thank you btw

My iMac:

8.1, 24", 2.88 GHz, HD2600 pro, 4Gb

* Fresh formatted en partitioned hard drive. Clean LION install. + mplayer No aditional software. No updates.

Very slow video performance (Mplayer / Flash)

* Updated (10.7.2)

No performance gain at all

I installed the mentioned .kext yesterday and the performance is back!

Will report back if the peformance issues are returning or if Apple has a solution.

Called Apple support to make a case.

Same thing... iMac8,1 (Early 2008) - 2.8Ghz, 4GB RAM w/ATI Radeon HD 2600 Pro. I waited until 10.7.2 - when I downloaded Lion upgrade from app store it went straight to 10.7.2 - no updates required.

I'm not a gamer, but I started searching as to why the OS animations are so slow on my machine and came across this thread. Maybe it has something to do with the revision of the card in our machines? My info from System Profiler:

Chipset Model: ATI Radeon HD 2600 Pro

Type: GPU

Bus: PCIe

PCIe Lane Width: x16

VRAM (Total): 256 MB

Vendor: ATI (0x1002)

Device ID: 0x9583

Revision ID: 0x0000

ROM Revision: 113-B2250L-259

EFI Driver Version: 01.00.259