3 interrupt assignments, Standard interrupt assignments, Irq assignments for this motherboard – Asus P5B User Manual
Page 42: These irqs are usually available for pci devices

2-8
Chapter 2: Hardware information
2.5.3
Interrupt assignments
Standard interrupt assignments
IRQ
Priority
Standard Function
0
System Timer
2
Keyboard Controller
2
—
Re-direct to IRQ#9
2
IRQ holder for PCI steering*
Communications Port (COM)*
5
IRQ holder for PCI steering*
6
5
Floppy Disk Controller
7
6
Printer Port (LPT)*
8
System CMOS/Real Time Clock
9
ACPI*
0
5
SMBus Controller*
6
IRQ holder for PCI steering*
2
7
PS/2 Compatible Mouse Port*
8
Numeric Data Processor
9
IDEIRQ (legacy mode, combined mapped as primary),
SMasterATA (Master), SATA (Secondary)
5
0
IDEIRQ (legacy mode, combined mapped as secondary),
SATA2 (Master), SATA (Secondary)
* These IRQs are usually available for PCI devices.
IRQ assignments for this motherboard
A
B
C
D
E
F
G
H
PCI
—
—
—
—
— shared —
—
PCI2
—
—
—
—
—
— shared —
PCI
—
—
—
—
—
—
— shared
PCIEX6_
shared —
—
—
—
—
—
—
PCIEX_
shared —
—
—
—
—
—
—
PCIEX_2
— shared
—
—
—
—
—
—
PCIEX_
—
—
shared —
—
—
—
—
On-board ESATA, SATA_RAID
shared —
—
—
—
—
—
—
On-board PRI_IDE
— shared
—
—
—
—
—
—
On-board HD Audio (ADI988A)
—
—
—
—
—
— shared —
On-board GbEthernet (RTL8B)
—
—
— shared —
—
—
—
USB 2.0 EHCI#
—
—
—
—
—
—
— shared
USB2 OBCI#
—
—
—
—
—
—
— shared
USB OBCI#2
—
—
— shared —
—
—
—
USB56 OBCI#
—
—
shared —
—
—
—
—
USB 2.0 EHCI#
—
—
shared —
—
—
—
—
USB78 OBCI#
— shared
—
—
—
—
—
—
USB90 OBCI#5
shared —
—
—
—
—
—
—
SATA, SATA2 (ICH8)
—
—
— shared —
—
—
—
SATA, SATA (ICH8)
—
—
— shared —
—
—
—