On Thursday 13 November 2008 10:40:03 am Joerg Sonnenberger wrote: > On Thu, Nov 13, 2008 at 02:40:54AM -0800, Jeremy Chadwick wrote: > > Otherwise, consider purchasing a motherboard that has an APIC (this is > > not a typo) increasing the IRQ count to 256. > > This is wrong. The first IO-APIC gives you 8 additional interrupts to > the 16 ISA interrupt lines. Every additional IO-APIC gives you 24 more. > Most modern chipsets have one IO-APIC, at least for non-embedded > systems. It doesn't mean you don't get interrupt sharing though.
I/O APICs are not hardwired to 24 pins. Early Pentium SMP systems actually only had 16 pins on their I/O APICs. I've seen I/O APICs with 32 pins, etc. There is a register in the I/O APIC that lets software know how many pins it contains. -- John Baldwin _______________________________________________ freebsd-hackers@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to "[EMAIL PROTECTED]"
