With Sandy Bridge and Ivy Bridge, standard Core i5 and i7 processors offer enough multiplier headroom for 400MHz overclocks. K-series chips are only required to push higher. Things are different for Haswell, which removes the multiplier allowance for standard CPUs, making multiplier-based overclocking exclusive to K-series processors."
You do software updates to get the most from favourite programs right? Updating a motherboard BIOS can in a timely manner is also critical. The guide to Flashing a Motherboard BIOS spells out the often complicated steps in plain english. PCSTATS Tips