Asus Rampage II Extreme - Manual (Page 55)

2. BIOS flash setting (6-pin BIOS_FLASHBACK)
Two sets of BIOS Flash ROM (BIOS 1 and BIOS 2) are present on this
motherboard. This jumper allows you to select either BIOS as the one to
boot, or back up or restore BIOS content from one ROM to the other.
Moving the jumper cap to pins 1-2 (default) allows you to enter BIOS MENU
to select which BIOS to boot.
Moving the jumper cap to pins 3-4 enables the system to boot from BIOS 1.
Moving the jumper cap to pins 5-6 enables the system to boot from BIOS 2.
Refer to 3.7.3 BIOS Boot Priority for further information.
ROG Rampage II Extreme 2-27