What's the deal with "IRQ steering"

[OuTpaTienT]

With IRQ steering Windoze seems to think it's perfectly ok for my devices to share IRQ's. Just the other day it had my PCI sound card, my ISA modem, and my AGP video card all sharing the same **** IRQ. And my modem wouldn't work in that configuration.

The stupid thing is, I have at least 4 free IRQs. Why the hell won't Windoze use them? Having Windoze is like have a retarded sibling to care for. Geeeez.

[BBA]

Windoze doesn't assign PCI Irq's, you motherboard does! Most ISA modems have hard coded IRQ's also, maybe with an optional jumper to change it, and, "if" it is "plug and play" it can be configured in device manager.

Almost all MB's use the identical resources for the AGP and the first PCI slot by design (it's more like a shared slot of sorts) but the AGP slot has a little different memory address abilities.

You should never put a PCI device that requires a IRQ next to an AGP card, or you are asking for problems.

Some motherboards will let you manually assign IRQ's to each PCI slot, so you might get some relief there, it will be a bios setting.

Hope this helps a little!

BBA

[This message has been edited by BBA (edited 07-11-99).]

[CMonster]

BBA - well it helps me to understand a little more clearly.

[krusty]

I had similar problems & just shut IRQ steering off. Seemed to fix things ok. Is this likely to cause any problems??