On Tue, 2004-06-01 at 08:14, Malcolm Baldridge wrote: > > So, am I completely hosed with my Adaptec SCSI drive setup? Anybody > > have any insight into these Adaptec controllers? I've fussed with the > > setpci latency_timer settings (from Jan Depner's "Installing and > > configuring ALSA, JACK, & Ardour..." web site), but still see long > > xruns. > If you could email the output from lspci -v and procinfo, that would be great. > > Also, which exact kernel setup are you using? Preemptible? > Preempt+low-latency? Con Kolivas' "LCK1" patches which combine O(1) > scheduler, and two sets of low-latency patches, including patches to the I/O > subsystem? > > Also, which filesystems are you using for your audio data drive? If you're > using ext3, which journalling mode? data=writeback seems to provide alot > better latency than the default data=ordered. Reiserfs seems to solve alot > of problems as well, if you're willing to reformat your audio drive. It's > easier to change your ext3 journalling mode (no reformat is necessary). > > What kind of SCSI drives are you using? I had these problems as well. There's a long thread a few months back where it was confirmed that I tried *everything*. Eventually I gave up and bought an IDE drive. Hey presto, problems gone. Now the only xruns happen when there's scsi disk activity, according to vmstat. The only time I didn't have these problems was with a MSI dual-athlon board that had a 64-bit PCI slot where the 29160 was plugged in. I only realised later (after the motherboard was on a ship to Taiwan, for a different reason) that the 64-bit slot was on a separate bus from the 32-bit slot where the audio card (Terratec EWS88MT) was plugged in. That board didn't give me xruns either. I think that's a plausible explanation, but then again it may have been because there were 2 cpus. On the other hand, I can't help wondering if the bus-greediness of the Adaptec controllers isn't a driver issue. I had a brief look at the driver sources, but I don't know enough about kernels and drivers to have made sense of them. bye John
