Comment 21 for bug 1049630

I am a long-time sufferer of this problem.
I have the Gateway LT3103u, which is

I have not yet applied Alex's patch, but I recently tried playing with the gartsize and vramlimit options.
gartsize seems to have no effect.
However, setting the vramlimit to 64 seems (2 reboots later) to clear up the corruption.
vramlimit of 128, 256, and 0 (0 is ignored) each result in corruption

The card normally reports 384 MB of vram and 512 MB of gtt memory.

Is it possible this computer is misreporting the amount of sideport ram? I read someplace that th x1270 can only have up to 128, but that there is some "Hypermemory" mumbo jumbo going on that adds some of your system ram to the mix.

Unfortunately, the Gateway LT3103u has a terrible bios config. you can't change anything, and you can't see much of anything either.

So, for the record: adding "radeon.vramlimit=64" to the kernel parameters in grub seems to alleviate the problem.

I'm running gentoo amd64, kernel 3.2.6-gentoo and git mesa