PCI USB card: why is this happening? (W2K)

[kef999]

If you were using a device in PCI slot 4, let's say, and you then move the card to PCI slot 2, say, would you have to uninstall the device first, ie. by software, before Windows can detect the device in the new PCI slot position?

I thought it was just a matter of physically moving the device (in this case, a USB card) from the one slot to the other, but when I did so and rebooted, the controllers and hubs belonging to that card completely disappeared from Device Manager.

Adding the USB card at all has caused three new IRQs to be produced, two of which now have to be shared with the AGP graphics card and the soundcard. So I'm experimenting with a couple of spare PCI slots that I still have, hoping to reduce the IRQ sharing by at least one IRQ.

If the only way that I'll be able to experiment with those spare slots is to uninstall the device, how exactly should that be done? In Device Manager, it's very difficult to tell which drivers in the listing belong to the PC's embedded USB ports and which ones belong to the new PCI USB card.

[BertImmenschuh]

Another case arises of "if it ain't broke, don't fix it".

If not having a problem, I wouldn't worry too much about freeing up IRQs in Win98SE/ME/2000/XP, most times IRQ Sharing works just fine with PCI motherboards.

My WinXP Pro on a Gigabyte board shows IRQs 0 through 22 and some of them have 2 devices assigned.

My Win2000 Pro on a Gigabyte board shows IRQs 0 through 23 in use.

There's two ways to identify the Add-in PCI USB 2.0 card, one is the entries in Device Manager that mention USB 2.0 or Standard Enhanced controller and the other is by the brand of chipset. My card has an NEC chipset while the motherboard/built-in USB is a VIA controller.

The only time I've had a problem was when the board chipset was an ALI and the card chipset was also an ALI, caused driver problems. Changing to a card with the NEC chipset worked.

<font color=blue>Good judgement comes from experience, and experience comes from bad judgement.</font color=blue>
<font color=green>Experience is a wonderful thing. It enables you to recognize a mistake when you make it again.</font color=green>

[kef999]

I have to admit that I've had similar thoughts, Bert; the sharing of certain IRQs perhaps isn't a sign of future problems with resource clashes. Nonetheless, historically, we've been advised to avoid IRQ sharing, where possible, and since I still have one or two spare PCI slots available, I thought it was worth experimenting to see if I could reduce the amount of current sharing by repositioning the Belkin card. It's just that I was surprised when Windows didn't then detect the card in a new slot. Could it be that you have to remove the card and then reboot, before refitting the card into a different slot?

The Belkin card does indeed use an NEC chip. However, if it's going to be a matter of identifying individual controllers and hubs to uninstall, before it's possible to reinstall the card in a different slot, it truly IS going to be tricky because, although one or two of the extra controllers installed for the Belkin card are easily identified by the NEC name, some five others aren't, as they have identical names to the Microsoft standard ones which are necessary for the PC's embedded USBs. I think that if I were to uninstall them, I'd have a very tricky job indeed to reinstall them for the new slot, as under Win2KSP4, getting the up-to-date Microsoft USB2.0 drivers installed isn't automatic, you have to manually update them by searching in SP4.

So, as you say, my best strategy might be to leave well alone. That is, leave things as they are and just hope that the sharing of those IRQs causes no problems.

My PC's an ACPI-configurable type and, since ACPI is default, that's precisely the type of PC that I have. This means that, inevitably, the BIOS takes control of device resources, allocating IRQs accordingly. The user has little or no influence on these allocations. As I understand it, this could be changed by making the PC into a non-ACPI device. That way, the user can then manually assign IRQs to the PCI bus. However, making the PC non-ACPI would mean a reinstall of the operating system - or so I'm led to believe [I notice that there's "ACPI enable/disable" in my BIOS] - and I sure ain't gonna do that! Not because I'm incapable but simply because of the very long time and the huge amount of work required to reinstall all my other software. I think that when you reinstall Win2K, you have to intervene at its very first bootup, to set the PC to a non-ACPI device. Correct me if I'm wrong.

[BertImmenschuh]

I have had to remove PCI Modems and reboot the computer as many as 3 times to get Windows to accept the installation again.

I have not seen a motherboard yet with more than the 16 IRQs [0 to 15] so disabling ACPI may not leave enough resources available to other add-ins.

I don't go with the 'updated Microsoft' drivers as I find they break things more than provide enhancements. Again, it's the "if it ain't broke" thing.

And Yes, changing some settings in the BIOS can force a clean re-install, but not always, so Windows picks up the resources available or not available by that change.

And you are right on the conserving of IRQs but that started changing with the advent of Win98 or Win98SE and the Sharing. I can't begin to enumerate the problems with modems and sound cards back in DOS and Win95 days in getting the IRQs right.

<font color=blue>Good judgement comes from experience, and experience comes from bad judgement.</font color=blue>
<font color=green>Experience is a wonderful thing. It enables you to recognize a mistake when you make it again.</font color=green>

[kef999]

Yes, I kinda agree with what you say.

I've now put back the Belkin card into its original PCI slot and I'll be leaving it there. If IRQs are now shared, so be it. I'm now keeping my fingers crossed that I won't encounter an IRQ clash when I start using the USB ports on that card.

It's just that I found it quite a surprise that the Belkin card required three IRQs. One spare IRQ was taken by it, the other two were IRQs already taken by the AGP card and the soundcard and so those two became shared. That said, when I look at my records, I see that my PC's embedded USBs take up four IRQs!

As things now stand, I've got no spare IRQs left at all, despite me actually using only three PCI cards. That's out of a total of 24 (IRQ0 - IRQ23). IRQ3 (COMPort2) and IRQ4 (COMPort1) are both disabled by me, both in Windows and in the BIOS, as is IRQ10 (Midi port). However, the BIOS will still not release those IRQs for usage. Also, I've noticed that IRQs 5 and 11 remain permanently reserved. Maybe those two are used by special systems components.

BTW, you commented "And yes, changing ....... can force a clean reinstall ..........by that change". In saying that, are you suggesting that perhaps my PC can revert to non-ACPI without the need to reinstall the OS and instead simply by changing the ACPI option in the BIOS?

[BertImmenschuh]

There's some changes that can be made in the BIOS and Windows won't care, other changes can give errors that can only be overcome by re-installing, don't have a list so it would be trial-and-error to see what can be done.

<font color=blue>Good judgement comes from experience, and experience comes from bad judgement.</font color=blue>
<font color=green>Experience is a wonderful thing. It enables you to recognize a mistake when you make it again.</font color=green>