--- Comment #11 from Jan Matejek firstname.lastname@example.org --- (In reply to Michael Chang from comment #10)
Looks to me that the video ram is too small to enable page flipping by swapping poiners of on-screen and off-screen buffers in video memory to update the screen quicky .
this is true, but doesn't help the issue
indeed, lowering to 1600x1200x32 (6400 line width, 15MB used) gets rid of the line-by-line rendering, and the whole image appears at once
BUT, there is still roughly the same delay before the image appears
so ISTM it's the filling of the buffer itself that is causing the slowdown