Memory voltage!!

Corsair make slots of RAM sticks.....w/o knowing what specific set (model no.) or even what CPU / memory controller is driving it, that's just about an impossible question to answer.

If it's an X58 / i7 system, the max voltage which the CPU's memory interface is rated for 1.65 volts. Most times you can run considerably lower.

Should also be noted that you should not go above 1.65V if you have an Intel system. Doing so will break your chip.