1600mhz ram running 1333mhz

Hello I've been wondering for some time and read a bit about it, but is it better to run my ram at 1333mhz with lower timings than running it at the recommended speed/timings?

Using a pair of corsair 4gig 1600mhz CL9 

  • CMZ8GX3M2A1600C9

With an amd fx 8120 on a gigabyte ga-990fxa-ud3
I'm new to messing with my ram and when I turned the ram up from 1333mhz to 1600mhz. When I did that it wouldn't post, so is it just a matter of turning the volts up a bit or?

Most (or maybe any) AMD boards don't have XMP, so you'll have to set the ram manually, that said I've never had trouble reaching XMP profiles or beyond with AMD boards. Manually set the frequency to 1600MHz, set the timings to 9-9-9 and set the voltage at 1.5V. It should run perfectly fine.