What are you trying to accomplish? OC RAM? I mean, I used to have some cheap RAM back then, but wanted to OC my memory beyond 1600Mhz. I had to bump up the voltage to 1.55 - 1.58 and never ran into issues, other than overheating, which is expected.
Typically, 1.35 -1.50 volts is safe to use (is this DDR3 right?), but it all depends on the RAM you are using.