ATI 4850 radeon graphics quality on openSUSE 11.3

I’ve just upgraded 11.2 to 11.3, and immediately found that scrolling images in Firefox (eg Google) quickly freezes the whole system.

I found a matching bug:
[Bug 625023] New: Hard system freeze when loading image in Firefox
which was analyzed and closed as a duplicate of
Bug 597078 - intel[G33]/nouveau [mi] EQ overflowing. The server is probably stuck in an infinite loop.

I followed the advice of the bug owner in his last post which was simply:
“Updating to libdrm, Mesa, xorg-x11-server and xorg-x11-driver-video
of obs://X11: XOrg might be worth a try. Hope this update doesn’t
make your issues worse.”
(and with that, the bug was marked “resolved”.) So I added the X11: Xorg repository and upgraded libdrm, Mesa, xorg-11-server, xorg-x11-driver-video, and it did resolve the freeze.

However, the aforementioned scrolling in Firefox is still very poor quality (images blank out, don’t move smoothly, jumping, really slow, etc). The quality improves if I use a much lower monitor resolution, say 1024x768, but that’s inadequate.

My lspci output for the card is:
sudo /sbin/lspci -v -k -s 04:00.0
04:00.0 VGA compatible controller: ATI Technologies Inc RV770 [Radeon HD 4850] (prog-if 00 [VGA controller])
Subsystem: Dell Device 0502
Flags: bus master, fast devsel, latency 0, IRQ 29
Memory at d0000000 (64-bit, prefetchable) [size=256]
Memory at fbee0000 (64-bit, non-prefetchable) [size=64]
I/O ports at e000 [size=256]
Expansion ROM at fbec0000 [disabled] [size=128]
Capabilities: [50] Power Management version 3
Capabilities: [58] Express Legacy Endpoint, MSI 00
Capabilities: [a0] MSI: Enable+ Count=1/1 Maskable- 64bit+
Capabilities: [100] Vendor Specific Information: ID=0001 Rev=1 Len=010 <?>
Kernel driver in use: radeon

Is there anything I can do to improve Firefox image/scrolling now that I’ve already updated the X11 drivers? The same bug effect Deskop Effects, which I also wanted to start using.[/size][/size][/size][/size]

Okay, After just posting the above, I turned on Desktop Effects, to test that, and immediately the image-scrolling issue disappeared. There doesn’t seem to be any other issues with desktop effects, either.

Any explanations?

Just pointing you to some info as I know little of ATI
openSUSE Graphic Card Practical Theory Guide for Users

Possibly ‘fglrx’ is an option. But I suggest you read and wait for more qualified replies.