Discovered another bug on ATI graphic chip linux driver.
Some of you may have noticed, if you install 32bits ubuntu 10.10 with 4G ram, it will automatically use the PAE kernel, which is a patch to the 32bits kernel to address all of the 4G ram. Sweet you may say.
Things took for a downward spin for my ATI chipset pc. After the ubuntu 10.10 install with 2 sticks of 2G ram, naturally the PAE kernel is in placed. My 2D desktop started giving lots of artifacts which made me ran to the shop couple times to change the board & ram thinking it's either the Biostar A880G+ board or the Kingston ram are having compatibility issue. 2 sticks of 2G ram with onboard graphic showing artifact, that is nothing new, so I thought. Unfortunately, new board & rams did not solve the problem. So I lived with the problem by using the 3D desktop, which miraculously has no artifact problem. Weird. And that was with the open source ati driver.
Lately, I tried to enable hardware accelerated HD video playback with the proprietary ATI driver & now the 'hardware accelerated' full HD playback is displayed in an even bigger mess... dropped frames, artifacts, messed up colors, tearing... I tried ATI driver version 11-1, 11-2 & 11-3 & no matter what I do, the problem persisted.
Then it daunts on me that the PAE kernel was at work. So, I reinstall ubuntu with 2G of ram alone & sure enough it installed the non-PAE kernel. What do you know, all the artifact, discoloration are gone... other problems like non-optimized hardware accelerated HD playback & high cpu utilization persisted. But those are, again nothing new for the poorly written ATI linux drivers.
So, could it be linux PAE kernel's problem, one ask? Not at all. I checked my other pc with 4G ram running the same version of PAE kernel, the 2D desktop, 3D desktop, hardware accelerated HD playback are all silky smooth, cpu utilization is low & stable. I even finished most of the Starcraft2 campaigns( except the final one ) on the onboard graphic chip, an it did all that flawlessly in linux with the PAE kernel & with 2 sticks of 2G ram.
It's nvidia 8300 onboard graphic chip. Kudos to nVidia.
Most people already knew ATI's windows drivers are a pain to install/remove compared to nVidia. I just have to say, ATI's linux drivers are even more buggy & much room for improvement.
A lesson to learn for the linux community. nVidia chipset is more linux friendly, always.
Bad news though, nvidia has since dropped out of the onboard graphic chipset race for DIY motherboard business. Intel won't let them in on their motherboard chipset business from i3, i5 & i7 series onward, except the OEM laptop & netbook segment. ATI won't let them in on their motherboard chipset business for obvious reason.
So, now the linux community is left with the buggy ATI graphic chips. Let's hope ATI will improve their linux support & give a better linux experience with their their graphic chips.
Let's also hope, Intel delivers the graphic drivers for their shinny & new Sandy Bridge chips soon. Words has it that, graphic support is only available from ubuntu 11.04 onwards. Which is another set back for the linux community.