Some questions about xf86-video-intel driver

[Simon Pasch]

 >> -The Kernel apggart driver reports that the AGP aperture size is
 >> 256MB. Is this possibly the reason, why X eats all the mem? (don't
 >> have a BIOS option to lower the AGP aperture size)
 >>
 >
 > Yes.
 >

So what can I do to lower memory usage?

Trying to use the Option "AperTexSize" in xorg.conf device-section 
doesn't change anything.

Or do I have to hack the intel_agp-code in the kernel? Just tried to 
hard-code the return value of the function intel_i9xx_fetch_size, but 
then X exits with error "Couldn't bind memory for front buffer".