if ur mobo is 1600 capable..no need to OC the bios will automatically handle the ram sticks
if 1333 ra kutob ang mobo , mu step down ur ram into the max ram speed the mobo can handle but with a tighter CAS settings
or u OC ur Procie with Assync or Sync settng RAM : FSB , that will make ur Mobo ran the RAM into a OC result relaxed 1600MHz speed < this is the gud thing on RAM with higher than mobo limitation speed