From:	"George Kinney" <goober AT mail DOT net>
Subject:	Re: Vesa 2.0 is slower than 1.2 on my video card !!!!!
Newsgroups:	comp.os.msdos.djgpp
References:	<ww03-BgugDj2843 AT netaddress DOT usa DOT net>
Organization:	The Unknown Programmers
Message-ID:	<01bc9649$c7c22620$c38033cf@pentium>
NNTP-Posting-Host:	207.51.128.195
Date:	22 Jul 97 02:39:11 GMT
Lines:	40
To:	djgpp AT delorie DOT com
DJ-Gateway:	from newsgroup comp.os.msdos.djgpp

Guan Foo Wah <jgfw AT usa DOT net> wrote in article
<ww03-BgugDj2843 AT netaddress DOT usa DOT net>...
> My video card's (Cirrus Logic Cl-54M30) bios doesn't support vesa 2.0 
> but vesa 1.2. I install the Display Doctor 5.3a into my computer so that 
> my video card can support vesa 2.0. 
> 
> Then I ran the Allegro's Demo.exe. I choose vesa 2.0 linear frame 
> buffer and 640x480 mode with double buffer. When the game starts, it 
> reported the frame rate to be 16 fps. This is even slower than the vesa
1.2 
> (which is about 24 fps with univbe and 22 without univbe). Can someone
tell 
> me why vesa 2.0 is slower in my video card when it suppose to be faster 
> ??? anyone ??

You are *emulating* VESA 2.0 extensions.  That means you have a driver
processing 
all your interactions, then sending it on to the card. This is just more
code 
that has to run everytime you plot something.  This takes more time. It's
like 
using an FPU emulator, instead of the native hardware. (Although I'll admit

that univbe isn't nearly that slow :)

Also, not all cards are compatible with the 2.0 extensions.  I don't know 
about the Cirrus you have, but you might want to get some specs on it and
find out.

Personally, I have an S3 Trio32 on-board, and it seems to benefit from
using 
a linear buffer. Sometimes though, it doesn't seem to have any effect.

I've tried a lot of computers to check video performance, and the 2.0
extensions
have resulted in a speed up on about half of them.  So it's not the holy
grail 
quite yet.

Anyways, good luck.

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