Everyone that knows me know about the troubles I’ve had with my HP Pavilion zv6148EA laptop and the built-in ATI XPRESS 200M GPU. The chipset has 128MB dedicated RAM but you can configure it to use up to 128MB of system RAM for a total of 256MB RAM. The first issue with this scheme is that there is a problem with either the GPU, the BIOS or the Video BIOS because the device always reports that it has 256MB RAM. The HP-branded ATI drivers that came with the Windows install seems to handle this just fine but when you use ATIs drivers on Linux (you can’t use the official ATI drivers on Windows as they refuse to install) the machine will deadlock unless you assign the GPU 128MB of system RAM so it actually totals 256MB. My assumption here being that HP modified ATIs drivers to properly detect the actual amount of RAM rather than fixing this damn bug properly. I have no use whatsoever for 256MB of video RAM so throwing away 128MB of valuable system RAM sucks big time.
I recently found this blog created by someone with the exact same problem as me which not only confirmed some of my fears but also asserts that this is not an ATI driver problem but rather a video BIOS bug.