3 Step Guide to Overclock Your i7 / i5 Haswell Platform | Overclockers

One thing that hasn’t changed with Haswell is that CPU clock is King. Regardless of what you do with the rest of your system, be it RAM clock, BCLK or any other clock, CPU clock is going to be the number one most important thing you can improve; thus, we start there. Before we get there, go into your UEFI, load optimized defaults, and to avoid any potential instability, set your RAM’s voltage to whatever it’s rated at (1.5 V or 1.65 V typically), leaving everything else on “Auto”.

Source – 3 Step Guide to Overclock Your i7 / i5 Haswell Platform | Overclockers.