Mail Archives: djgpp/1997/06/10/23:51:24
I threw together a quick test tonight to figure out exactly
what kind of performance I could expect to get out of allegro
for my computer. What I have is:
Cyrix 686 P150+ Chip
16meg 70ns Ram (not EDO)
82430HX Chipset
and most Importantly: Creative Labs 3D Blaster
Now, not expecting to be wowed at all by my 3D Blaster (which
I have full intentions on replacing soon, it sucks), I created
a test program to figure out the max number of blits I could
make each second. I was shocked by the results. Not at all
what I expected. Here are the results under Windows 95:
Tested: 640,480 for 20 seconds
VGA Frames = 53.9 - Expected slow, but not this slow
Vesa 1.0 Frames = 133.6 - Believable
Vesa Banked Frames = 155.4 - A little faster, expected this
Linear Frame Buffer = 114.1 - Whoa, did not expect this
Why is the linear frame buffer SLOWER than the banked? Weird,
so I tried it a few more times (only one shown):
Tested: 640,480 for 20 seconds
VGA Frames = 53.85
Vesa 1.0 Frames = 143.25
Vesa Banked Frames = 154.8
Linear Frame Buffer = 114.5
Yeah, it's definately slower. Very strange. Anybody know what
can account for this? I suppose it's just crappy design on the
part of Creative Labs. I do also have the most recent bios on
the card.
Ok, none of this really has anything to do with DJGPP and Allegro.
So why am I posting this here? Well, with the Vesa 2.0 Banked
Emulation mode, the bitmap was only blitting to the upper 20% of
the screen, and the rest remained blank. Shawn, if you want me
to help you track down another bug, I can give it a shot. I
suspect, however, once again that it's just crappy design on the
part of Creative Labs. I'll try it with UniVBE when I get a chance
and report back if that fixes the problem.
- Raw text -