Apr 21, 2009
I have a Dell T3400 workstation with Vista 64 Ultimate that I am using for editing video with Vegas Video Pro 9.0c. I have a PreSonus Firepod external firewire sound card that is hooked up to a PCI firewire card.

I am not sure, but I think I am having IRQ conflicts. When I select the Firepod in Windows Sound, the sound usually works well for a while after a fresh bootup, but then after a few hours (give or take a few hours), it drops out. Sometimes I can get the sound back by switching from 44.1 to 48.0 HMz (or vice versa), which is what leads me to believe I ay have an IRQ conflict). Other times I have to reboot in order to get sound back. THen other times, even rebooting does not help, and so I have to switch to external speakers. I can run that way, but I cannot use any of the XLR-inputs, meaning I cannot record, or dub.

I checked the IRQ assignments, and I have seven different devices assigned to PCI (IRQ) 16. I am told that one can reassign them in XP, but not in Vista (or in 7). Are IRQ's assigned by the motherboard? Or by the chipset? And why can I not manually reassign them in Vista? If I had a different motherboard, would I likely get different IRQ assignments?

I tried inserting a picture, but I could not figure out how to search by URL, unless this is it.

PCI 16 has:
High Definition Audio Controller (Motherboard audio?)
Intel ICH9 Family PCI Express Root Port 1 - 2940
Intel ICH9 Family USB Universal Host Controller - 2937
Intel X38 Express Chipset PCI Express Root Port - 29E1
PCI standard PCI-to-PCI bridge
Texas Instruments OHCI Compliant IEEE 1394 Host Contoller (new firewire card with TI chipset)

The first entry is Windows Sound, and the last entry is the firewire card, which runs the Firepod/firewire card. I imagine that having them both on PCI 16 is my problem, but since Microsoft did not enable manual reassignment of IRQ's with Vista, I don't know how to change it.

Is there some way to get different IRQ assignments, short of a new motherboard?

Thank you.



Feb 18, 2008
check bios for option about plug and play os installed.
When IRQS bunch up as one, windows is letting the system create spaces,
when you select yes, windows assigns different IRQs. And vista does do this as well, just like XP.
if bios does not have the option. you got a stubborn one, move things around.