You make sure your CPU is underclocked, and nothing else is clocked higher then normal, then you slowly increase your mem until it doesn't run anymore at that voltage, then you increase voltage, and again increase mhz, then you decrease timings a bit if you want, and so on and son. So, its all about increasing clock, increasing voltage and loosening timings, and finding out what is the best it can do, which combination is the best. All the while you must make sure nothing else in your system is overclocked so that when you cannot boot or pass memtest you know its only your memory and nothing else.