Whats up man, i have the same MOBO, its a bitch to OC with. It can do a great job but u have to find the perfect voltages witch i have failed to do. Anyhow the jumper is located in the bottom right portion of the mobo/ SW of the sata ports.
If you find a good setup for ur OC pls let me know. Ive been trying for days and only really got it to work really well overclocked to 3.1GHz. I got it to run at 3.2, but the temps weren't worth it. To even get my CPU to run at a FSB of 1600MHz i had to up Vcore pretty f-in high, like the 1.5ish range. Should rarely have to go that high. I may have just gotten a gimped CPU, or a gimped Board, pls let me know how ur OCing goes.