you can change divider ram in the bios set to 1600 for default get @800 (in Cpu-z) with it mean run at 1600 and little increase Vdim. (max 1.65v)
and first you must loosen the timing first, then test with the IBT if result stable you can tighten it again and test again and so on.
and test stability use Intel burntest
set High/Maximum in 20 loop maybe less than 15minute