graphic card & IRQ sharing = performance decrease ??

[ShePearl]

Hi, folks.

Currently,my Radeon 9700 Pro is sharing its IRQ 16 with onboard Intel USB controller - Intel 82801EB USB Host Controller.

I'm using Pentium4C 3.4 GHz (800 MHz FSB)
1 GB Mushkin PC3200 2-2-2 Special (BH-6)
ATi AIW Radeon 9700 Pro (soon to be replaced with NV40 or R420)
Shuttle SB75G2 (i875P Canterwood)
Windows XP Professional Service Pack 1a + latest updates.

Stability is NOT an issue. But I'd like to know if my 9700's (and/or future NV40 or R420) sharing IRQ 16 with Intel 82801EB USB Host Controller decreases any performace ??

I've been out of loops for about 4 years, and back in the old days of Windows 98, I remember sharing IRQ very often leads to stability issues as well as performance decrease.

I'm hearing these days of ACPI motherboard, and hardwares plus Windows XP does proper job of handling IRQ sharings. But what about performance-wise ??

All I'm using in my USB port is an USB mouse, so I can disable USB controllers in BIOS, and use PS/2 mouse instead.

What are your thoughts, folks ?

Sharing IRQ 16 between USB controller and graphic cards = performace decrease ??

Any cooments, opinions, advice would be greatly appreciated.

Cheers.

 

[davefb]

quick answer . it's no problem , win2k , xp ( and nt4?) can share irq's to your hearts content... i assume it's something to do with 'virtualizing' the physical irq . .

-dave-

 

[Nick Spolec]

You can stop it from sharing with the USB.

If you can, you have to go into your motherboard's bios (unless you have some shit Compaq/Dell computer) and disable the option called "Assign IRQ for USB".

Your USB will still get an IRQ, just not an IRQ that is already assigned (such as, my video card is IRQ 16, and my USB is 20/21/22)