From:	Ludvig Larsson <ludvig AT club-internet DOT fr>
Newsgroups:	comp.os.msdos.djgpp
Subject:	Line frame buffer speed problem
Date:	Mon, 15 Feb 1999 15:26:12 +0100
Organization:	Faas-Goldhart
Lines:	41
Message-ID:	<36C82E49.FDA@club-internet.fr>
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To:	djgpp AT delorie DOT com
DJ-Gateway:	from newsgroup comp.os.msdos.djgpp
Reply-To:	djgpp AT delorie DOT com

Hi!

I have got a small problem.

I have a graphic library(done with DJGPP offcourse) which
I use in several applications.
Well, I'm currently working on a 3D-viewer and the banked modes
doesn't make life easy so I rebuilded it with mode-detection
and LineFrameBuffer support.

And performance dropped almost 70%...

I have an old Matrox Millennium and I thought that maybe there
were some drivers that wasn't up to date or something, so I got
SciTech Display Doctor and it updated a lot of stuff, but
still, the performance is really bad with LFB.

The testvalues from SciTech Display Control Center:

mode: 640x480x16bit: Banked

Clr screen: 75Mb/sec
BitBlt:     55Mb/sec

mode: 640x480x16bit: Linear buffer

Clr screen: 21Mb/sec
BitBlt:     19Mb/sec


Well, so I have an old card, but do I need to make
my library support LFB And Banked modes(as a commercial product)
or is my card broken/to old?

Any suggestions for a workaround would be highly appreciated.


Ludvig Larsson

ps. Sorry for this a bit offtopic question, but I really don't know what
to do.

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