Seems that with RTIRQ another layer of virtual interrupts is created, great, but.... I reckon it might be better to put sound card ahead of hard disk which is still on physical irq 14/15 where agp is on 16, sound card is on 17 and onboard is on 23. (That combined with another disk software layer added with LVM (not that LVM hasnt got its advantages...) in FC3 slowing it down) Anyone got any ideas how the set up of RTIRQ (if thats actually what is doing it) virtual IRQ assignments is done? only running on an XP1600+, trying to squeeze a bit more out of it... 48Khz low latency is pretty steady recording in ardour , but alsa_pcm xruns at 96khz (happen about every 20 secs, seem to coincide with disk access) particularly recording in ardour. Jack rack running multiple effects at same 96khz 3.67ms latency is much more steady, roughly 1 dropout every 10 minutes, and thats with me messing around in the background in gnome browsing, writing this etc.. (but not doing much HD access...) in fact it seems so consistent that it may be some process every 9.x mins causing this. still thoroughly impressed though, 3ms latency stereo at 96kHz... reliable enough to run jaaa .... and RT effects... Nice!