Originally posted by JohnDiamant
Thanks. Does a PCI slot always correspond to the same IRQ (if I move a different card into the slot, will it always get the IRQ that the previous card had)?
How can I tell which USB controller is being used by which USB device (and does switching USB plugs change that)?
I ask because all of my PCI slots are occupied by "high performance devices" (when considering MCE/AV capture and playback as the applications) so I don't really know what I can do to get them to not share an IRQ. My cards are: audio, video (AGP slot), analog tuner, digital tuner. I have no spare slots, so all I can do is move them around. I assume the video card needs to stay in the AGP slot, so can only move around the tuners and audio. Right now, my audio uses the same IRQ as video, but if I were able to make them use different IRQs, but have the tuners either share IRQ with each other (bad for recording two shows at once) or one of the tuners share with the audio instead (bad for recording and watching at the same time), that seems like I'm just trading off one problem for another. I'd like to find out how to avoid any IRQ conflicts for any device involved in AV recording or playback (I didn't mention I have a USB disk, so I wouldn't want to create a conflict with that either, which currently may also share the IRQ with audio and video -- I have 4 USB controllers showing in device manager, but can't tell which is being used by the disk, and one of them conflicts).
Generally, the BIOS or the operating system (Windows) will assign IRQ to PCI slots. However, some motherboards will always assign a particular IRQ to a particular PCI slot. But, you can change them in the BIOS settings.
But, as you are doing, it may be easier simply to move the cards from one slot to another.
You may have to sacrifice that audio card if you can tolerate the builtin audio, as a last resort.
Let's consider these factors. Of the four cards you use, the HDTV Wonder should be considered the heavy lifter because it processes high definition video. If you can isolate an IRQ for the HDTV Wonder, then do so.
Next, the analog tuner is probably a hardware encoder; that it, video processing is done on the card itself instead in software, which means the CPU does the processing. So, the analog card might share an IRQ fairly well, particularly if it has good software drivers. Excellent drivers might cure all such issues.
If the audio card does hardware processing, then the same applies. Despite its apparent reputation for good audio cards, Creative Labs Sound Blaster audio cards have been known to be finicky. It used to be that you had to isolate the SB with its own IRQ, otherwise the sound would sputter and pop. I have no experience with the current SB models.
With respect to the USB devices, in the Device Manager at the bottom, there will be listed within the Universal Serial Bus Controollers' section several USB Root Hubs. Selecting and double-clicking each Hub will bring up the properties of the Hub.
Under the "Power" tab, you will see which USB device is associated with that particular USB Hub. If you check the properties of all the USB HUBs listed, you can figure out which HUB Hub is associated with which physical USB port.