EVGA P55 FTW - Manual (Page 29)

The Red wires should be occupying the pins on the top row.
Now, access the Disable/Enable Function at the front of the Control Panel:
From Right to Left, PCIE Slots 1,2,3. When Jumper is in top position, PCIE
slot is enabled. When in bottom position PCIE slot is disabled. Above shows
example of PCIE slot 2 disabled while the rest are enabled.
CPU VCore Booster
For convenience of users when overclocking, the ECP houses 2 CPU Vcore
Boosters for real-time boost of CPU VCore upwards of +0.1v per button.