[linux-audio-dev] M-Audio and jack

Hi all, I have a Compaq Presario notebook with an AMD64 3000+ and I am trying to use an M-Audio MobilePre for home studio and realtime effects. This machine comes with an nforce3 chipset, including an intel8x0 sound card. I have a 2.6.12rc4-mm2 kernel with the realtime module loaded. I also have tmpfs mounted on /tmp I have two problems with jack: With the intel8x0 I can get jackd to run smoothly, but sometimes (when launching some program for example) I get many xruns even with realtime scheduling. Here's how I start it: jackd -R -d alsa -d "hw:0" -p128 -n2 -S -r48000 but still, it works quite decently. I tried this with realtime effects (ecamegapedal) and no problem. However, if I try the same configuration with the the M-Audio card (which is mapped to card 2, full duplex is implicit) jackd -R -d alsa -d "hw:2" -p128 -n2 -S -r48000 I get a lot of xruns. Then, if I try something like jackd -R -d alsa -d "hw:2" -p512 -n2 -S -r48000 I get NO xruns either, but the sound is completely "chopped". This only stops happening with a period size of 2048!! Of course, at this point I can only use it as a recording/playback device but I have to forget about realtime effects! I know that the USB 2.0 bandwidth is more than enough to work in full duplex mode with two channels at 48000hz (even USB 1.1 bandwidth is enough for this purposes). Can it be something about the snd-usb-audio driver being too slow? Any suggestions? Thanks, Ignacio Ramirez.-