Message-ID:	<360C5E1C.F8F784BB@mailexcite.com>
Date:	Fri, 25 Sep 1998 23:23:09 -0400
From:	Doug Gale <dgale AT mailexcite DOT com>
MIME-Version:	1.0
Newsgroups:	comp.os.msdos.djgpp
Subject:	Re: Why is D3D faster?
References:	<360a6153 DOT 0 AT news1 DOT mweb DOT co DOT za> <6uh08h$dup$1 AT nclient3-gui DOT server DOT ntli DOT net> <6uh736$m8g$1 AT pulp DOT ucs DOT ualberta DOT ca>
NNTP-Posting-Host:	oshawaisdn97.idirect.com
Organization:	"Usenet User"
Lines:	17
To:	djgpp AT delorie DOT com
DJ-Gateway:	from newsgroup comp.os.msdos.djgpp

> Could you please explain why D3D under window is faster than DOS if
> the system has a 3D accelerator?
>
> Mandr

It is faster because Direct3D can use any hardware acceleration present on the video
card. Most 3D accelerators have special hardware to draw triangles and texture map
them. Usually, the CPU just has to send a bunch of command to the accelerator's
command buffer. The accelerator does the drawing (usually using specialized FAST
hardware), and generates an interrupt when most of the commands have been executed.
Then the CPU just uploads more commands to the card, and the cycle repeats. This has
the extra benefit of freeing the CPU up to do other stuff.

- Raw text -