Asus OC Tuner
The biggest problem with pre-defined overclocking profiles is that they can’t adjust for normal variations in a CPU's scalability. One Core i5-2500K might be able to hit 4.3 GHz without a problem, while another maxes out at 4.5 GHz. Asus addresses that issue with an overclocking engine that alternates between stability tests and incremental clock increases to more precisely isolate the overclocking limit of your chip. The best part of Asus’ method is its single-step initialization.
Clicking “OK” from the OC Tuner menu initiates the process, which is followed by a reboot, around a minute of black screen, and a new set of voltage and clock values.
We were a little disappointed to see the top-overclocking P8Z68 Deluxe yield only 4.43 GHz using its automated method. But our biggest concern was that it ramped our CPU core up to 1.448 V under certain load conditions. Several of our hardcore overclocking friends have given us a 1.45 V peak instantaneous voltage limit for Intel Sandy Bridge-based processors, and our own tests have shown that exceeding 1.40 V for extended periods dramatically decreases the processor’s life.
OC Tuner ignores our memory’s XMP capability, but does increase its multiplier to the DDR3-1866 setting. Combining that with the processor’s higher 103 MHz BCLK yields an actual data rate of DDR3-1923.