Under 24 bit mode, no
acceleration, the 3d board is quite usable even without the fast
update option, although the animation is a little bit jerky. Gnubg
says it's about 0.4 fps which it refers to as extremely slow.
tried 16 bit mode. Now gnubg says it's very fast and, with shadows
disabled, it is blindingly fast with very smooth animations. But if
shadows are enabled. the shadows simply become seemingly random dark
patches over the board - it looks like it's got some particularly
unpleasant form of video eczema.
Is there any assumption of 24 bpp modes in the shadow code, or is it
likely to be a driver problem? The only other test I had to hand was
glxgears, which animates perfectly in 16 bit mode.