I have an ABIT KN9 motherboard. It has one PCI-e x16 slot, three PCI-e x4 slots and two legacy PCI. My problem is with the legacy PCI (which I shall just call "PCI".) I currently have an Nvidia GeForce 8600 GT (a low end card) installed in the x16 slot and a TV card in PCI #1; the x4 slots are unused, as is PCI #2. I plan to upgrade the graphics card soon, the current card was spare. I sometimes install a USB expander in PCI #2 but it causes a lot of problems - see below.

The problem is under Linux (Ubuntu 10.10, Linux 2.6.35-22-generic), but probably under all operating systems (I have not yet been able to test Windows, but I suspect it will do the same as the problems occur on the BIOS/POST side too, e.g. when using a USB keyboard on the expander the keyboard will not work at all) PCI has an enourmous delay, and packets arrive in large chunks. For example, when using the USB expander, my USB mouse lags and jumps in large steps every second or so, while using the motherboard USB does not present this problem. My TV card will only do one or two frames per second, and the program (xawtv) usually times out and crashes. In dmesg, I'm getting messages like:

bttv0: timeout: drop=74, irq=154/100476, risc=31f6256c, bits: VSYNC HSYNC OFLOW RISCI

for my TV card, and similar timeout issues for my USB expander with a mouse.

I received the motherboard, processor and RAM second hand and have only just got around to building it, so I don't know if this problem has always existed, or if it's a result of my set up. If anyone has any hints or solutions it would be appreciated - this is kind of a show-stopper for me.