[linux-audio-user] kernel latency question

[rico]

Every now and then i try to turn my linux box into an audio station.
I'm a musician and want to use band in a box.
I recently switched from mandrake to debian because i want to have a better 
understanding/control on my system.
I use timidity as i don't own a midi sound card.

config (amd athlon 1.4 nv driver snd-ens1371)
dual boot->debian sarge(2.6.8 alsa debug+ preemption + voluntary_preemption 
patch)
		->mandrake 10.0 (2.6.3-15-mdk no preemption no patch besides mandrake 
applied to its stock kernel. what patches? i don't know)

1.Band in a box (with wine)

Well my problem is that i cannot get the system (debian) to run band in a box 
without cratches and glitches  whereas it works flawlessly under mandrake!
I tried various patches and hints (http://www.affenbande.org/~tapas)
i still can't make it work.
I even tried to compile mandrake kernel source under debian but raised many 
other pbs so i gave up..
So ok i stick on mandrake since it works there...
But since it does work with mdk i should be able to make it work on debian!
Helas not!
How comes it works on mandrake and not on debian?
Any hint anybody?

2. Jack realtime + realtime module + softsynth

Igualito, using jack + qsynth (or even timidity) turns out to be impossible 
(thousands of xruns, crappy sound, sometimes  X  crashes )
when i use realtime the system(atically) crashes 
thousands of xruns
mandrake or debian : it is pretty unusable.

I tried changing the IRQs from threaded to not threaded, changing the latency 
with setpci, to no avail.
The only thing that improved the xruns a little is:
echo 16 > /sys/block/hda/queue/max_sectors_kb


If some of you managed to solve theis kind of problem (cheap soundcard, no 
midi harware) i would like them to share their experience.

There is probably something i didn't or i did wrong! 



Cheers
Eric