On Sat, 2004-07-17 at 06:33, Malcolm Baldridge wrote: > > Slight side issue, while you guys are on the subject. > > > > I have my soundcard (an onboard i8x0) sharing an interrupt (IRQ 11) with > > eth0 and usb-uhci. Would this be likely to give rise to xruns in a > > similar way? > > I think motherboard audio bugs/latency issues will be more of a problem than > shared IRQs. Turning off the PnP Setting in the BIOS and then "Reset > Configuration Data" may cause a re-assignment to occur during the next time > you go through BIOS POST. > > > or is it just a question of physically moving the ethernet card? > > Moving the ethernet card should get you another IRQ, though keep in mind, > it's a bit stranger with PCI than ISA. To make it even spicier, some PCI > slots are not capable of bus-mastering DMA. But the answer to your question > is yes: moving the card will get you a different IRQ. > It may take a few tries to get everything where you want it though. > As for the onboard-USB, well, that might be harder to "move". The problem > is that the IRQs are "mapped" to PCI INT-levels, and it seems that many > system hardware designers get very lazy and slopping with how they use them. > > Shared IRQs have been with us for a few years now, and I doubt it's the > source of most xruns people see on their systems these days. We are talking > about microseconds of additional time to determine the interrupt source > here. If your xruns are in the hundreds of milliseconds, this is not your > problem. If you're on the borderlines, THEN it might be something worth > looking into. > In addition to the time to determine interrupt source there is another problem with shared interrupts - don't use any USB devices or run your network while trying to record. Jan
