ASUS P5Q WS 2-21
3. PCI-X Speed setting (3-pin PCIX_SPEED)
This jumper allows you to set the PCI-X slot’s maximum frequency capability.
The jumper cap on pins 1-2: 133 MHz capability for the PCI-X slot.
The jumper cap on pins 2-3: 100 MHz capability for the PCI-X slot.