i have never noticed an increase ever due to overclocking things. we are talking about the difference in maybe 10 fps since memory, cpu, and gpu can only oc the tiny bit 10-15%. but any hardware that CAN even overclock high enough to do this, was good enough to not need overclocking at all. thats the funny thing.
if the base parts cant run games at minimal settings, then overclocking isnt going to improve it.