Abit IP35-E and IRQs

[LMarsh]

Hi,

I?m thinking of buying an Abit IP35-E. I?m wondering if the PCI slots share IRQs with anything, and if so, is it possible to assign them an individual IRQ manually?

Thanks.

 

[SerpentRoyal]

DO NOT tweak IRQs unless there is an issue. Windows will often share IRQ between chipset and video.

http://support.microsoft.com/kb/314068

In accordance with the Plug and Play capability that is defined by the PCI specification, adapters are configured by the computer BIOS and are then examined by the operating system and changed if necessary. Typically, PCI devices have IRQs shared among them, especially on Advanced Configuration and Power Interface (ACPI) computers that have Windows ACPI support enabled.

Manually assigning IRQs to PCI slots in the system BIOS as a troubleshooting method may work on some non-ACPI systems that use a standard PC hardware abstraction layer (HAL), but these settings are ignored by Plug and Play in Windows if ACPI support is enabled. If you must manually assign IRQ addresses through the BIOS to a device on an ACPI motherboard, you must reinstall Windows to force the installation to use a Standard PC HAL.

 

[Miramonti]

This thread gives me flashbacks of the nightmares I had resolving Windows NT irq conflicts.

 

[LMarsh]

Thanks Serpent. But is it even possble to assign the IRQs manually (and set the PC to standard) in the IP35-E's bios. I understand bioses on some boards don't even have these options?

I'd never do it if it wasn't absolutely necessary, mind you. (I'd probably manage to f*ck it up royally.) 😉

 

[SerpentRoyal]

I don't see an option to change IRQ in manual. May need to review. You can download the manual at Abit's website.

 

[LMarsh]

Thanks Serpent. I tried downloading it and the only thing I could find was this:

http://bp3.blogger.com/_7-fOI_...Qpo/s1600-h/ip35-e.jpg

Not sure if "Choose the specific IRQ resources in the ?IRQ Resources? menu." means you can manually assign IRQ's to the various components? (Don't have much experience with this, as you can probably tell.) 🙂

 

[SerpentRoyal]

Looks like you may be able to tweak in BIOS. I've never had any IRQ issue as long as I clean install the OS.

 

[Peter]

Ah stop that, guys. Despite the popular "irq sharing" mythology, shared interrupts are NOT a problem on PCI (and its siblings AGP and PCIE). In fact, interrupt sharing is a (mandatory) feature of the PCI specification.

And besides, the interrupt hookups are a mainboard PCB design choice, and as such are not programmable anyway. What used to be programmable is the routing of these hookups onto legacy PIC interrupt lines. Ever since operating systems are running the APIC interrupt controllers natively, this is irrelevant.

In fact, the entire topic is irrelevant unless you're in the middle of writing a BIOS for a new mainboard design.

 

[LMarsh]

Thanks.