irq's

[richnsue]

in my system information it list the irq's from 0 to 15 and i notice that not all the numbers are used, perhaps because i have disabled some things i don't need like serial ports, but even so,
several numbers are being used by more than one device. so should i change them so all numbers are used and as few as possible are being shared, and is this best done in the bios?

[frnkzks]

Don't worry about it. Unlike ISA devises, a single IRQ number can be shared among multiple PCI devices.

Idealy, you don't want all your ICQs to be used if you want to add more devices later.

[Imperion1]

If you're using Win2k then most add-on devices will be on 1 IRQ. There is a way to prevent this, but I don't remember how. It has to do with the APM setting in your bios, I believe.

If its Win98 or 98SE then the AGP vid card needs to be on an IRQ of its own. Unless you have a video capture card, then these can share the same IRQ. The soundcard can share an IRQ with an NIC, modem, or both.

Lets see if I remember this correctly.
For a Raid board w/ 6 PCI slots.
AGP and PCI1 share an IRQ.
PCI2 and PCI3 share an IRQ.
PCI4 and PCI6 share an IRQ.
PCI5 and Raid controller share and IRQ.

Non-Raid w/ 6 PCI slots.
Only difference I believe is that PCI5 doesn't share unless you have a soundcard or NIC in this slot.

5 PCI slot board.
AGP and PCI1 share.
PCI2 and PCI4 share.
PCI3 and PCI5 share.
and if there is an ISA slot then it shares the same IRQ as PCI5.

I could be a little off on this though.

[richnsue]

thanks folks, i'm not sure yet whether to change anything. i'm using windows ME and have an agp card and a pci sound card. the other 4 pci slots are not used and not likely to be. seems a shame that 3 of the irq's are not in use.

[D`Sypher]

Well i would say change nothing, unless there is a problem.

But I would think about moving any devices on IRQ2 and 9
as these are the redirectors.