Well if doom 3 can run its prolly ok systemwise
Good point, missed that one.
Something else:
The syntax of the 'graphics' command changed slightly -- you can now also specify the refreshrate, and BlitzMax will automagically try to time its screen updates to fit into this.
Maybe you're trying to specify 16bit color, but are accidentally telling it to limit your framerate to 16 FPS (16 Hz)?
try using just graphics 800,600 without any additional parameters, and see if that makes a difference in the speed you're getting...
Alternatively, what kind of FPS are you seeing after calling this statement:
bglSetSwapInterval(0)
(It will disable the Vertical Wait, and give you the 'real' speed of your screen updates, regardless of the actual refreshrate of your video mode. Although it doesn't seem to work on all cards)