hi,
I think you have 2 options. First, you could try to update the BIOS. Newer versions may support reserving more memory for video.well, i cn get newer bios, but that can be flashed only using m$. since i alredy deleted the windows partition, it's not an option.
If that doesn't work, you could try using 855patch. It's a program available at http://www.chzsoft.com.ar/855patch.html. Once you read the instructions and download the program, you'll need to edit your xorg.conf file:this works like a charm! no problems, i just allocate 16mb and voila... the speedup isn't in fact dramatic, but i didn't expect much... still i get 30% speedup (when comparing the fps before and now)by adding a line Load "dri" to the Section "Module" by using the Driver "i810" in the Section "Device" by setting VideoRam to the desired value in the Section "Device"
thank you for excellent hint! best regards, -- Lubos _@_"