IRQ problem on 8KRA2+

[p.pitchford]

I have just purchased a 8kra2+ mobo and seem to have a problem.

When booting all the devices are shared by 4 or 5 IRQ's.This does not look correct as I have a USB device and the onboard sound on the same IRQ. When I try installing windows XP I get an IRQL error while installing the software.

My other machine ( Different manufacturers mobo ) displays all the devices on board it with different IRQ's and woks fine.

I have windows98 previously installed and it does boot correctly but the sound is not correct and when I check the hardwre IRQ's there are 5 devices on IRQ 11.


Can any one help ?

[EPoX Tech]

The error that you are getting in installation sounds very much like a memory error or similar stability based error - not of IRQ.

It is normal for VIA based mainboards to share IRQ's - what is more important is interupt addresing through PCI mastering if add in cards are used.

[yecnad]

Fact is some devices/drivers will quite happily share an IRQ and others won't. There are many sound and graphic cards that will not work properly if they have to share an IRQ, the SB Audigy and GF4 in my system will not work and cause erratic behaviour and crashes in Windows if they share an IRQ.

I disabled the on board sound, game port, SATA and serial/parallel ports to free as many resources as possible (i.e. disable any devices you do not use). Despite placing my sound card in a PCI slot that according to the manual only shares an IRQ with another PCI slot (PCI 4 & PCI 6) it would always share an IRQ with another device. As the KRA2+ will not let you assign a specific IRQ to an interrupt and the only way I could get my sound card to work was to experiment with reserving IRQ's for legacy devices. Eventually I reserved IRQ5 which left my sound card by its self on IRQ 7 and all my problems disappeared.

The Epox Tech may still be right but his answer seems to steer you away from any IRQ issues which is not necessarily correct.

[p.pitchford]

The thing I find odd is I know you can share an IRQ say com1 & com3 share one but I seem to have about 5 items on the same IRQ.

I will look at the memory first as this sounds like it may be the issue.

[Áedán]

On the PCI bus, the specification quite clearly states that support for interrupt sharing is mandatory. Unfortunately some drivers are badly written, and cannot cope with interrupt sharing under heavy loads.

Alas, this doesn't really help you very much.