Why Can't I Separate Video Card and USB?

Dyre Straits · Jul 23, 2005, 01:03 AM

For some reason, my IC7-G with Windows XP Pro SP2, latest Intel Drivers, latest BIOS Update (28) and every new driver I can think of installed, I still cannot get my vidcard to use a currently unused IRQ.

I've never had this problem on previous ABIT boards. Of course, I hadn't used Windows XP, either.

But, I'm using USB Keyboard and Mouse on USB 2.0 in my games. AND, every once in a while, my games crash without any particular error recorded. I'm just highly suspicious that having the Vidcard and USB Devices all on IRQ 16 is the source of the problem.

I just upgraded my video card yesterday from an ATi 9600 Pro 128 MB DDR card to an ATi X800 XL 256 MB DDR3 card and it also got assigned IRQ 16.

Under previous systems, I had no problem getting the card to use IRQ 10, or some other IRQ that isn't in use. But, not on this one.

Ðamage™ · Jul 23, 2005, 01:52 AM

Do you have your APIC mode enabled?

Dyre Straits · Jul 23, 2005, 02:04 AM

Quote:

Originally Posted by Ðamage™

Do you have your APIC mode enabled?

Yes. That's why IRQ 16 shows up at all.

Ðamage™ · Jul 23, 2005, 02:16 AM

Manually assign interrupt request (IRQ) line numbers for each hardware device

Some x86-based motherboards force IRQ sharing across two or more expansion slots (or integrated devices) regardless of the adapters installed. In some cases, IRQ sharing can cause conflicts after you install new hardware. If you have a non-ACPI computer equipped with firmware that supports changing IRQ assignments, as a troubleshooting method, try manually changing the IRQ assigned to a problem device.

Because systems that use the ACPI HAL ignore IRQ assignments stored in firmware, you are only able to manually change IRQ settings for non-ACPI (Standard PC HAL) systems. Some x86-based systems enable you to toggle ACPI functionality. To disable or re-enable ACPI, you must first change firmware settings and then re-install Windows XP Professional to avoid a Stop 0xA5 message or a Stop 0x79 message. Because of the numerous registry and system file changes required, you must rerun Setup (an upgrade installation does not work).

Basically if you want to able to do this, your going to have to disable APIC and reformat, sorry bro. I might be wrong but everything I've read about changing IRQ's leads to this everytime.

Cheers

Zelig · Jul 23, 2005, 07:40 AM

Hmm... I wouldn't be surprised if that doesn't really help your problem... I've never seen shared assigned IRQs cause problems in either XP or newish distros, I've always been able to solve problems I've seen by means other than changing IRQs.

Necrosis · Jul 23, 2005, 01:42 PM

How you turned everything off in your bios that you don't need?

Dyre Straits · Jul 23, 2005, 03:20 PM

Quote:

Originally Posted by Necrosis

How you turned everything off in your bios that you don't need?

Well, for one thing, I've tried Disabling the ASSIGN IRQ for USB. I've even tried Disabling ASSIGN IRQ for VIDEO ADAPTER. Then I reboot and check assignments.

It just always come back up to having these devices on IRQ 16

Dyre Straits · Jul 24, 2005, 01:03 AM

UPDATE:

According to a response on the ABIT forums, the reason these two devices cannot be separated is due to the way Intel wired the 875 chipset. For whatever ungodly reason, Intel decided to make the USB2.0 and the AGP share the same IRQ!

So, if this is true, anyone with an 875 chipset suffers the same fate. I can't even begin to imagine why any designer would FORCE the AGP BUS to share an IRQ with anything else whatsoever.

Also, from what little research I've been able to come up with, the report of game crashes with thiis configuration isn't all too uncommon.

Since I've only had my IC7-G for about 6 months now, I'll have to live with it until I really, really want to upgrade to PCIe. That'll likely be early next year -- if not the end of this year. (Might be a nice Christmas/Birthday gift to myself.

)

The_Neon_Cowboy · Jul 24, 2005, 03:11 AM

Quote:

Originally Posted by Dyre Straits

UPDATE:

According to a response on the ABIT forums, the reason these two devices cannot be separated is due to the way Intel wired the 875 chipset. For whatever ungodly reason, Intel decided to make the USB2.0 and the AGP share the same IRQ!

So, if this is true, anyone with an 875 chipset suffers the same fate. I can't even begin to imagine why any designer would FORCE the AGP BUS to share an IRQ with anything else whatsoever.

Also, from what little research I've been able to come up with, the report of game crashes with thiis configuration isn't all too uncommon.

Since I've only had my IC7-G for about 6 months now, I'll have to live with it until I really, really want to upgrade to PCIe. That'll likely be early next year -- if not the end of this year. (Might be a nice Christmas/Birthday gift to myself.

)

Acually doesn't AGP share a resource on all boards useally the same
as the 1st pci slot or Least it used to...

I think

But I just looked at my RS480 chipset board and PCIe and USB are both
are on IRQ 18... Can't see with my Nforce4 bard as it down for a bit but
I bet it's the same. I use a USB mouse and basic ps2 keyboard with out
problems.

Have you tried checking adjusting the latencys with this tool?? might help...
http://downloads.guru3d.com/download.php?det=951
Run the tool and post a screen shot of what things are reading out...

Zelig · Jul 24, 2005, 11:01 AM

Quote:

Originally Posted by The_Neon_Cowboy

But I just looked at my RS480 chipset board and PCIe and USB are both
are on IRQ 18... Can't see with my Nforce4 bard as it down for a bit but
I bet it's the same. I use a USB mouse and basic ps2 keyboard with out
problems.

Yeah, my nForce4 board shares PCI-express and one of the ethernet controllers on IRQ 18, and I haven't had any problems because of that.

Dyre Straits · Jul 24, 2005, 02:12 PM

OK, I'm not sure if I'm onto something or not. BUT, last night when I got home I went into the BIOS and Disabled the IRQ for USB. Rebooted and played Morrowind -- still using USB mouse and keyboard -- for about 4 hours straight. Never once had a crash. I believe that's the longest I've gone in the game in one session without some kind of crash.

I'll monitor and update this over the next few days.

Dyre Straits · Jul 25, 2005, 02:53 PM

UPDATE:

Last night I, again, got over 3 hours of constant play with Morrowind. I hadn't actually intended to spend that much time, but, wanted to push and push to see how long it would go.

Well, after about 3 1/2 hours, it finally did CTD. Only this time, there was never any Windows Error Report nor even the ATi VPU Recover Report. It simply just went to the Desktop and that was that.

So, maybe it was something else altogether. Nothing even shows up in the Activity Logs.

The only real downside to having the IRQ disabled for the USB is that I can no longer use my mult-device Memory Card and USB 2.0 connector that I installed to one of the 5 1/4" drive bays. That's going to be kind of aggravating to enable/disable USB between games and other sessions.

Dyre Straits · Jul 28, 2005, 07:04 PM

CORRECTION and UPDATE:

I found out that I CAN use my USB devices but the connector had come loose while working on the inside of the case. [oops!]

Also, I have had about 3 more CTDs during several hours of Morrowind. Still not sure just why.