Using the attached scripted setpci commands I have gotten the audio latency of my crusoe laptop down to 3 ms. Throughput to anything but the audio device is worse, but who cares when you're just running one audio synthesis/analysis process? I might crank up the pci latency of the ide controller if I ever need to stream audio to or from disk. Results of latencytest are posted at http://www.ouroboros-complex.org/latency.
My present kernel and alsa packages can be found at http://www.ouroboros-complex.org/moon. These are compatible with the Planet CCRMA project. See http://www.ouroboros-complex.org/moon/README. I have effectively reduced the weight of my rig from 120 to 2 pounds. Jack still doesn't work, but I can do pretty much everything in one Pd process anyway. It's no huge MOTM system, but then again, it's not a huge MOTM either. Thank you everyone. -- (jfm3 2838 BCBA 93BA 3058 ED95 A42C 37DB 66D1 B43C 9FD0)
#!/bin/bash #"open up" the PCI bus by allowing fairly long bursts for all devices, increasing performance #setpci -v -d *:* latency_timer=b0 #maximize latency timers for audio, allowing it to transmit more data per burst, preventing buffer over/underrun conditions setpci -v -s 00:06.0 latency_timer=ff # north bridge setpci -v -s 00:00.0 latency_timer=40 # firewire setpci -v -s 00:09.0 latency_timer=10 # ethernet setpci -v -s 00:0b.0 latency_timer=10 # usb setpci -v -s 00:0f.0 latency_timer=10 # ide setpci -v -s 00:10.0 latency_timer=10 # cardbus bridge setpci -v -s 00:12.0 latency_timer=40 # usb setpci -v -s 00:14.0 latency_timer=10
