On Fri, 2004-07-16 at 07:28, Mark Knecht wrote: > Florin Andrei wrote: > > > > Without APIC, the nvidia module was alone on its own interrupt, the > > EMU10K1 was alone, the ide and eth modules were on separate interrupts, > > etc. Quite ok. > > > > With IO-APIC, nvidia, EMU10K1 and bttv were on the same interrupt, ide2, > > ide3 and eth0 were on the same interrupt. > > Please note - The 'optimal' numerical assignment of interrupts with > using the APIC model has nothing to do with the older, non-APIC, order. > Please do not confuse the idea that 'interrupt #9 is best' with the > numbers assigned on an APIC system. These are completely different models. Well, the thing is, without APIC (default with Fedora single-CPU kernels) there was some overlap in the way the devices were assigned interrupts. Nothing bad (especially since the EMU10K1 got it's own IRQ), but still i thought there is room for improvement. So, since IO-APIC usually provides more interrupts, i thought, well, if there are more IRQs available, the kernel might find a better way to assign them. The reality is quite the opposite. With IO-APIC the IRQs suffer from more overlapping than without it. Which is kind of strange to me. BTW, the mobo is based on the NForce v1 chipset. -- Florin Andrei http://florin.myip.org/
