Help understanding IRQ assignments and troubleshooting

I've been going over and over trying to solve a problem on my PC for the last few days, and while it's not an issue worthy of another thread, I do have some questions that you experienced guys might be able to either explain, help or point me towards understanding.

I'm pretty fluent in computers, I've been building them since I was 9 years old, so that makes about 21 years worth of seeing things break.

One element that I never really got into, due to not experiencing, is understanding and troubleshooting IRQ conflicts. I have a massive list of entries in my device manager, and some of them share an IRQ entry with other items. Would I see any improvement in stability by putting, for example, the video card on its own IRQ channel, if my PC's only problem is freezing shortly after launching a 3d game?

My video card is actually sharing an IRQ assignment with the 1394 and 4 USB controllers. Bleh, I'm noob all over again

IRQs aren't really used as much in modern computers as far as I know. From my understanding, they were used more with older Programmable Interrupt Controllers (PIC) and configured in the BIOS.

With the Advanced PICs, these have 255 physical IRQ lines per PIC, and from reading, which means, I could be wrong, that you could have 255 IRQ in a single PIC with no conflicts.

So I suppose you wouldn't notice a difference on a modern PC.

That's what I thought, I've never really studied it, since I've never really needed it. BUT anyone who claims to know computers say 'IRQ' like an emo says 'hate me' - I'm like uh, yeah sure. However this recent problem that seems to stump all my efforts at resolving has forced me into places I don't generally want to be lol

IRQ conflicts used to be a real problem. But I haven't seen that be a real issue for years, now.

I will add this Everlong's post: Your operating system is also capable of creating software/virtual IRQ's.

For example: If you open up System Information on your Vista machine, you may see some IRQ's up in the millions.

Here's an interesting article on ISA vs PCI Interupts: http://e-articles.info/e/a/title/IRQ`s-~-ISA-interrupts-versus-PCI-interrupts/

so if that is the case, there is no reason i shouldn't have my video and audio devices on their own channel? i understand that some devices sharing an irq channel may actually increase performance, but i fail to see how stacking usb inputs and 1394 channels with my video is in that realm of improvement.

Kwirl said:

so if that is the case, there is no reason i shouldn't have my video and audio devices on their own channel? i understand that some devices sharing an irq channel may actually increase performance, but i fail to see how stacking usb inputs and 1394 channels with my video is in that realm of improvement.

Click to expand...

It's neither a performance increase or decrease, as far as I know, these days.

IRQ's are still around, but they're a lot less of a problem than they used to be. Unless you get an actual conflict listed in the device manager, I'd say don't worry about 'em.