Depends on what platform.
If you’re on a modern intel socket (LGA 1155, 1156, 1150, 1151) then it might give you a few percents better performance, but it’s not really worth your time for the performance gains. if you’re OC’ing on those platforms, do it for the fun of the process, not the destination.
In most cases, you can barely see any performance gains; however, they still aren’t entirely noticeable when used in applications.
In the case of AMD APUs, the graphics cards and the processor share resources from the RAM and an overclocked RAM on an AMD APU will almost always show meaningful performance gains.