Changing device latency and IRQ used?

[trodas]

I would like to ask if anyone know, from where originate the latency setting, that after installing Windows use/set for certain devices. For example a latency setting for PCI NIC card.

If I know where they originate, I can hope I can change them to something reasonable w/o using another program (and I just like to know what is this about...)




Also I'm dying to know, from where the Windows/mainboard get the idea to use IRQ 7 for all the intensive tasks like GFX, SFX and NIC:



WTF?!
And how I can change / edit that. I keep the "Allocate IRQ for USB" enabled in BIOS, but also USB are on IRQ 7...
And I did not see used IRQ numbers 2, 3, 4, 5, 10 and 11.

I know that IRQ 2 are for some "cascade interrupt for IRQ 8-15" (whatever that menas) and IRQ 3 and 4 are mostly for COM 2 and COM 1 respectively, but I did not use either, so I can find a better usage for these IRQs.
But most importantly, the IRQ 5 is typically used by soundcard and I would like it to be used JUST for that! So, how?!
IRQ 7 is typically for parallel port, but when disabled it seems that all the hardware end up there...
Yet it still leave the IRQ 10 and 11 free to be used by GFX card and NIC card respectively, witch will leave on IRQ 7 the USB controller.
( http://www.webopedia.com/quick_ref/IRQnumbers.asp )

Now all that sounds good, but how I can re-arrange these IRQs?
(Windows 2000 SP4, JetWay V266B, AXP 150x12.5, 1024MB 2-2-2-5 ram, Realtek RTL8183(A) PCI NIC card, AGP GF2MX400 graphic card)