Asus Rampage III Black Edition - Manual (Page 53)

5. PCIe x16 Lane switch
These slide switches allows you to enable and disable the corresponding
PCIe x16 slots. When one of the installed PCIe x16 cards is out of order, you
can use the slide switch to find out the faulty one without removing the cards.
6. Q reset button
When the LN2�Mode jumper does not work and your CPU cannot resume
function, press the Q reset button to temporarily stop the power supply to the
CPU and help the CPU recover from a frozen condition.
ASUS Rampage III Black Edition 2-21