I was just wondering if anyone knows if it is normal to have your AGP Video Card showing up in Device Manager as running in PCI Bus 1? I have heard to update your motherboard chipset but nothing changed when I did.

I have a custom build Intel P4 3.0Ghz processor, ASUS P4P800 motherboard, 2GHz of RAM, a PNY NVIDIA Geforce 7800 GS video card, and a SoundBlaster X-Fi Extreme PCI sound card.

I also would like to know if it is normal to have your AGP video card sharing an IRQ with the USB Universal Host Controller? Sound card is sharing an IRQ with another USB Universal Host Controller.

Thanks ahead of time for any response.

I just went through the same questions building my P4, which is very similar to yours
If you really want to know how it all works, then you can download the motherboard manual, and study the schematics, but in a nutshell, here's how it works:
1) While based on the PCI local bus specification, AGP is independent of the PCI local bus.
2) Advanced pci devices "share" the IRQ only in the respect to the fact that they are all multiply it into eight other "alias" IRQs.(Programmable interrupt request, or PIRQ signals). They all "share" the same IRQ, because they have in common the fact that they can utilize PIRQ multiplexing, which is why you could theoretically have up to 127 USB devices hooked up at once, all on "one" "IRQ"
3) Contrarilly, "legacy" devices need their own "IRQ" because they don't have the advanced charactaristics to use multiplexing. That is why windows wouldn't report a "device conflict" If you check the "device connection by type" you will see memory addressing and fancy juggling by the various controllers, hubs, buzzers bells and whistles!
4) I bet your machine works as well as mine, and if it works, then don't fix it!
I hope this helps!