Weird features of Intel GX chipset

[Argo]

I just noticed that PERC RAID controller we have at work uses IRQs 48 and something else. Does it mean that GX based boards have more IRQs? Why can't they do the same on regular chipsets then?

 

[xtreme2k]

are you sure it reads IRQ 48? not IRQ 4,8?

 

[Methodical]

I believe the GX supports virtual IRQ's.

yet another way to solve the problem of the limitations of an old architecture.

 

[samgau]

From what I have noticed with our servers and PC's, its a feature of Windows NT/2000, also present in Linux and MAC OS, for example, my win2000 PC has a nic sitting on IRQ 32, and its a regular dell Pentium II 333...so it seems to be an OS feature.

just my 2c

Sam

 

[ElFenix]

macs did have more icqs, though. 32 i think.

 

[Lore]

Yeah, I noticed that on an Intel L440GX board as well. However, I think Windows 2000 is the real "culprit" behind those virtual IRQs.

 

[SUOrangeman]

I think one of my dual-CPU BX boards at work hos up to 60 IRQs. I had never heard about virtual IRQs until reading this thread, LOL.

-SUO

 

[Zach]

I thought I heard of people using ACPI (or whatever that damn acronym is) with Windows 2000 and ending up with phoney IRQ's being used?......

 

[Pariah]

IRQ's are an OS "feature." The ones the motherboard assigns aren't set in stone. In linux you will see things on IRQ #'s in the 100's.

 

[AndyHui]

Virtual IRQs are an OS feature rather than a chipset's. Win2K supports up to 255 virtual IRQs, usually in ACPI mode. When everything is sitting on IRQ9, IRQ9 actually works as a gateway to all those higher virtual IRQs above 15. Sure, performance might be a little slower than if each device was on its own 'real' IRQ, but at least it works.

 

[samgau]

Just what thought... I noticed that when I started working full time with WinNT... since then i was used to win95/98 15 irq limit... and i regularly cursed whoever set that limit... *laffs*

Sam out

 

[Lore]

I think Win95/98 got around that IRQ limitation as well, by setting up IRQ steering and allowing devices to share IRQs. You know, I remember when technical support for video cards/sound cards/NICs used to always say "Do not share any IRQs" yet I don't think I've ever had a problem with IRQ sharing.

 

[Argo]

Yeah, but I think there is a limit to how many devices can share an IRQ. I have seen a message like this before: "Not enough resources for device blah blah."