[geeks] Best Vista story I've seen

[Charles Shannon Hendrix]

On Tue, 20 Feb 2007 08:38:11 -0500
"Francois Dion" <francois.dion at gmail.com> wrote:

> On 2/20/07, Lionel Peterson <lionel4287 at verizon.net> wrote:
> > On Mon, 2007-02-19 at 21:11, Joshua Boyd wrote:
> > > On Mon, Feb 19, 2007 at 08:52:07PM -0500, Charles Shannon Hendrix wrote:
> > >
> > > > I also heard that a lot of Vista sound drivers are unaccelerated,
> > > > which seems to jive with previous Microsoft statements about not
> > > > supporting accelerated sound hardware.
> > >
> > > Interestingly, DirectSound3D support is dropped.  Also dropped is
> > > hardware mixing for DirectSound.  However, OpenAL drivers can still
> > > accellerate whatever they want to, so games that chose to use OpenAL (a
> > > cross platform standard, prefered by Apple and supported on Linux) will
> > > still get accelerated sound.
> >
> > Maybe I'm just being dense, but what, exactly is an accelerated sound
> > driver?
> >
> > Lionel
> 
> The best example ever is the Gravis Ultrasound. The GF1 chip had
> independant access to memory on the card and so you could assign each
> channel it's own memory buffer (actually, multiple buffers was). Even
> at 32 channels, all you had to do to play 32 streams, was to feed the
> buffers. The card did the frequency conversion, panning and the volume
> (and a few other things), then mixed the channels into a stereo pair.
> That is why the GUS was popular with the demo scene. It left all your
> cpu cycles to do math and video.
> 
> So hardware mixing is the most common use of "accelerated" support.
> The vast majority of games nowadays however simply use wav mixing for
> sound effects, 

Sorry, but that's not true.

Yes, most games offer simple wave mixing, but only for people whose sound
support sucks.

The vast majority of games with a focus on sound effects use hardware EAX, and
have for years now.

Miles 2D (the primary wave mixing 3D API) is nice if that's all your hardware
will support, but it is nothing like full EAX support.

> the music is all CD audio. That's a shame because the
> music is no longer interactive. If all you are doing is mixing a few
> sound effects, there is no need for hardware mixing, that is just
> trivial to do.

Trivial, but subject to latency penalties and game stuttering when your
system is very busy, and it can't offer many features.

Again, Miles 2D does a very good job all things considered, but the
difference between Miles 2D and something like EAX 4.0 is amazing.

Not only does everything sound better with EAX, but the CPU load is much
lower.

In F.E.A.R., I got a 20% improvement in frame rate during sound-complex
scenes, and wave mixing generally lost a ton of effects and there was a lot
of clipping.  EAX 4.0.... smooth as butter and sounds great.


-- 
shannon           | It's a damn poor mind that can only think of one way 
                  | to spell a word.
                  |         -- Andrew Jackson