Mail Archives: djgpp/1997/06/13/05:48:18
Bryan Murphy writes:
>and most Importantly: Creative Labs 3D Blaster
>
>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):
That is indeed very strange. What video resolution were these tests
running in? Because if the VGA was 320x200 while the VESA was 640x480,
those results are actually pretty close to an exact inverse of what I'd
expect :-)
If you have a copy of the profile.exe that comes with UniVBE, it would
be worth trying it to confirm whether the speed difference is iom any
way related to Allegro ('profile 101' to test the banked mode, and
'profile 4101' for a linear framebuffer).
>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
Very strange. It would be useful if you could check this with UniVBE
installed: I tend to be suspicious of other VESA drivers :-) Also, if
you have a copy of the vesainfo program from GRX, can you send me a copy
of the output you get from running that? (if not write to me by private
email, and I'll send you a copy...)
--
Shawn Hargreaves - shawn AT talula DOT demon DOT co DOT uk - http://www.talula.demon.co.uk/
Beauty is a French phonetic corruption of a short cloth neck ornament.
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