I have a GTS450 running on Centos 6 and latest released nvidia drivers 280.13 in a htpc box with mythtv . I am using the HDMI for my audio and while the sound works ok , I am getting messages in the logs that alsa is not happy with buffer size :
2011-09-03 20:24:11.819 ALSA, Error: Setting hardware audio buffer size to 576
2011-09-03 20:24:11.819 ALSA, Error: Error opening /proc/asound/card1/pcm3p/sub0/prealloc: Permission denied.
2011-09-03 20:24:11.819 ALSA, Error: Try to manually increase audio buffer with: echo 576 | sudo tee /proc/asound/card1/pcm3p/sub0/prealloc
2011-09-03 20:24:11.819 ALSA, Error: Unable to sufficiently increase ALSA hardware buffer size - underruns are likely
2011-09-03 20:28:25.870 ALSA, Error: WriteAudio: buffer underrun
2011-09-03 20:28:26.259 ALSA, Error: WriteAudio: buffer underrun
2011-09-03 20:28:26.815 ALSA, Error: WriteAudio: buffer underrun
2011-09-03 20:28:37.837 ALSA, Error: WriteAudio: buffer underrun
So I tried manually increasing the buffer , but not working :
root@htpc ~ # echo 576 > /proc/asound/card1/pcm3p/sub0/prealloc
root@htpc ~ # cat /proc/asound/card1/pcm3p/sub0/prealloc
root@htpc ~ #
Can not seem to budge it from 64K .Any Advice much appreciated .