[Openal-devel] Default buffer size

[Lukasz Pawelczyk]

Chris Robinson wrote:
> I've played around with the setting a bit, and 4096 doesn't seem to cause me
> any problems (but then, I have an AMD Athlon X2 4200+). My main hesitation
> about lowering the default buffer size to 4096, or lower, comes from the
> effects on low-end systems, which I obviously don't have. I want to make sure
> that turning it down like that won't reintroduce skipping or noise that was
> prevelant in the SI.

So it seems I've run on this problem as well.

AMD Athlon(tm) 64 X2 Dual Core Processor 5200+
Sound Blaster Audigy 2 ZS using ALSA, 1.0.16 kernel, 1.0.15 userspace.
Kernel 2.6.26
Not using any sound daemons, directly to alsa.
 From the above I can assume mmap is working for me.

Tested on:
FS2_open (www.hard-light.net)
X3 beta (www.linuxgamepublishing.com)

On 8096 delay is definitely too big for me. When hovering mouse over 
menus in both games they produce click sound. This is significantly 
delayed. Same with laser shooting. You first see the laser som distance 
in front of you then you hear it.
4096 is better, but still too big for me. No statics yet.
2096 is good, barely hear the delay (this value is acceptable for me).
Unfortunately statics begin here. Very rarely, but they do.
1024, this would be optimal in terms of delay. More statics. They start 
to be annoying.
512, no hearable difference between 1024 in terms of delay. A lot of 
statics.

And now most important for me, cause I don't get it:

1. If you ask me on those 2 games under windows the delay is on 1024 
level. And still no statics. Isn't that possible to be achieved on Linux?

2. What value SI had?

3. Why mmap is not helping? All above tests are with it turned on. When 
I turn it off I hear no difference. Statics appear on 2048 regardless of 
it. How can I check whether it really works? Point me to the place in 
code where this is determined, I'll make some printf there.


-- 
Regards    Havner                     {jid,mail}:havner(at)pld-linux.org
                    "Quis custodiet ipsos custodes?"