Did you put jacks tempfiles on a tmpfs partition ? I regularily change /tmp to a tmpfs partition in /etc/fstab these days. none /tmp tmpfs default 0 0 or something like that... /Robert torsdagen den 18 december 2003 11.35 skrev John Anderson: > I'm using ardour to do around 8 tracks of audio, not all have regions > active all the time. Playing a session through the first time, I get > grrrtz every so often, usually but not always accompanied by an xrun > report from jack. It's correlated with disk activity. Which is a Fujitsu > MAN3367 on an Adaptec 29160 and according to hdparm can do around > 50Mb/s. Although in ardour the disk throughput indicator shows anything > from 9 to 14, depending on the number of regions being played, and the > scheduler settings in use. I guess that's because the disk has to seek > for the data for various different regions. Which are on a Reiserfs > partition. > > I'm using an Athlon 2200+ on an MSI motherboard with 1Gb of memory. This > is after my nice dual-athlon motherboard died, which had none of these > problems. <sigh> > > I'm using 2.6.0-test11 kernel (with pre-emption), and I've tried the as > scheduler (with various settings), the cfq scheduler and the deadline > scheduler (which seemed to be the worst for this kind of low-latency > work). It's subjectively better than 2.4.22 with low-latency and > pre-emption patches. > > top shows that whenever there's a dropout, the CPU has just spent > anything from 6 to 30% on io wait. > > It's definitely not a sound card issue - once the session has played > through once and the audio files are cached, I get flawless playback > with ardour showing disk throughput of 190Mb/s, even with a compile > going in the background. I spent a few days playing with PCI latencies > as well, but that didn't make a difference. Dropping the SCSI controller > tagged queue depth to 4 makes recording more reliable, but doesn't > really help otherwise. > > It also doesn't seem to make much of a difference if I run jack with > buffer size of 1024 or 256. I haven't tried lower than that, and the > card (Terratec EWS88MT) won't go higher that -n 2 -p 2048. > > Short of getting another dualie motherboard (which is a PITA in this > country, and expensive), is there anything else I can try? low-latency > patches for 2.6 kernels? > > thanks > John
