Radeon 9800: change IRQ?

[Ken Krone]

I use a Radeon 9000 Pro under Win2000 and the IRQ requested by the card
is 16, which is shared by my USB controller. An external hdd that I
would like to use does not work on my computer because of the shared
IRQ. When I have tried to change the IRQ in Windows, the ability to
change the IRQ is grayed out.

Is there some way to alter the IRQ request from the 9000 Pro so that it
can be assigned another IRQ?

Thanks
Ken K

 

[dino]

the only way to reassign IRQ's is in the BIOS...and am not sure if you can
even do that for an AGP slot

 

[Ken K]

I could only find IRQ assignements for the PCI slots.

 

[JAD]

try changing the setting 'PnP OS installed'? to NO - reset
configuration data to YES in the bios....


My radeons use 11 most times.

 

[Ben Pope]

Well mine (Crucial 9800 Pro) is using 19 at the moment. It's not fixed
there though, that's assigned using ACPI with the advantage of APIC. I
think ACPI is the reason the option to change resources is greyed out.

I would suggest that you can move your Radeon from 16 (which is an odd one,
for a start - I take it you have APIC as well), but I don't know how - try
looking in the BIOS for ACPI stuff resource configuration. Nothing uses
IRQ16 in my machine.

Tricky one... as suggested if you let Windows do it, it might go one way, if
you let the BIOS do it, it'll likely be different, so change your PnP OS in
the BIOS. And changing the IRQ assignments in the BIOS might also allow you
to shift which devices conflict.

If you tell us your motherboard, and conflicting devices, we might be able
to help.

Ben

 

[Ken Krone]

Thank you so much for responding. I am sorry to not mention the
motherboard. It is an ASUS P4PE.

I need a quick primer in definitions of APIC and ACPI and how they can
be used in this process. In the meanwhile, I will change the BIOS
settings to PnP OS=no and see what happens when I boot up.

The conflicting devices are, as listed, Resource Device
IRQ 16 SAPPHIRE RADEON 9000 ATLANTIS PRO
IRQ 16 Intel(R) 82801DB/DBM USB Universal Host Controller - 24C2
(there are actually 3 USB controller, one each at 24C2, 24C6, and 24C7,
but only the one at 24C2 uses IRQ16.

I will change the BIOS and get back to you.

Thanks
Ken K

 

[Ken K]

I changed the BIOS PnP OS to no; there was no change.... Both devices
are still assigned to IRQ 16.

 

[Ken Krone]

I changed the BIOS choice for PnP OS to NO, but there was no change.
Both devices are still assigned to IRQ 16

 

[Ken K]

I changed the BIOS to PnP=NO but there was no change. Both devices are
assigned to IRQ 16.

 

[Ken Krone]

Oops. The ATI model is the 9000, not the 9800.... Sorry.

 

[Ben Pope]

Oops. The ATI model is the 9000, not the 9800.... Sorry.

I know, just an example.

Ben

 

[Ben Pope]

I changed the BIOS to PnP=NO but there was no change. Both devices are
assigned to IRQ 16.

Have tried changing which devices share an IRQ in the BIOS? If you look
carefully at the manual and compare with the BIOS options, you should find
that you can change which PCI slots/devices share with the AGP slot.

Looks like the manual says you can explicitly set IRQs for slots.

ftp://www.asus.it/pub/ASUS/mb/sock478/p4pe/e1110_p4pe.pdf

Section 4.4.3, page 4-26

Ben

 

[Ben Pope]

Have tried changing which devices share an IRQ in the BIOS? If you look
carefully at the manual and compare with the BIOS options, you should find
that you can change which PCI slots/devices share with the AGP slot.

Looks like the manual says you can explicitly set IRQs for slots.

ftp://www.asus.it/pub/ASUS/mb/sock478/p4pe/e1110_p4pe.pdf

Section 4.4.3, page 4-26

Grrr, wasn't done, hit the wrong button.

Shame you can't set the IRQ of th AGP, usually the configuration options for
IRQ is a little different, it might allow you to change the AGP IRQ.

I still think that your USB and VGA should be happy sharing an IRQ...

Ben

 

[J. Clarke]

Thank you so much for responding. I am sorry to not mention the
motherboard. It is an ASUS P4PE.

I need a quick primer in definitions of APIC and ACPI and how they can
be used in this process. In the meanwhile, I will change the BIOS
settings to PnP OS=no and see what happens when I boot up.

Won't do a thing. With ACPI enabled Windows ignores the BIOS and does
whatever it wants to with the IRQs. To set them manually you have to
reinstall Windows with the non-ACPI HAL.

ACPI stands for "Advanced Configuration and Power Interface" and it
basically lets Windows reconfigure the machine to suit itself. APIC is the
"Advanced Programmable Interrupt Controller" that allows more than 15
interrupts.

 

[Ken K]

Thanks for the info about ACPI and APIC. I have since discovered that
the mb is designed to share the same IRQ for the AGP slot and the first
USB host controller. My wife's computer has a similar set up and when I
tried the external USB hard drive on her computer, it works fine, so I
suspect that there is some issue with the operating system, and not the
IRQ's that does not allow the unit to be seen as a drive on my system.

Thanks
Ken K

 

[Ken K]

Thanks for the info about ACPI and APIC. I have since discovered that
the mb is designed to share the same IRQ for the AGP slot and the first
USB host controller. My wife's computer has a similar set up and when I
tried the external USB hard drive on her computer, it works fine, so I
suspect that there is some issue with the operating system, and not the
IRQ's that does not allow the unit to be seen as a drive on my system.

Thanks
Ken K