with APIC, USB, COM2 and LPT ports disabled: # cat /proc/interrupts CPU0 0: 974826 XT-PIC timer 1: 931 XT-PIC i8042 2: 0 XT-PIC cascade 3: 0 XT-PIC NVidia nForce2 5: 951920 XT-PIC wctdm 8: 4 XT-PIC rtc 9: 0 XT-PIC acpi 10: 633 XT-PIC eth1 11: 97616 XT-PIC eth0 12: 58 XT-PIC i8042 14: 8769 XT-PIC ide0 NMI: 0 LOC: 974784 ERR: 12887 MIS: 0 with APIC enabled: # cat /proc/interrupts CPU0 0: 27557553 XT-PIC timer 7: 258636 IO-APIC-edge parport0 8: 4 IO-APIC-edge rtc 9: 0 IO-APIC-level acpi 14: 117381 IO-APIC-edge ide0 177: 3439328 IO-APIC-level ohci_hcd, eth0 185: 0 IO-APIC-level ohci_hcd, NVidia nForce2 193: 1 IO-APIC-level ehci_hcd 201: 27529176 IO-APIC-level wctdm 209: 38569 IO-APIC-level eth1 NMI: 0 LOC: 27558945 ERR: 0 MIS: 0