Yes My system is overclocked, system specs in my sig.
I only gave general info on the voltages because the needed voltage will be different for every type of motherboard. 790i is similar to my 780i so bumping up the MCP,FSB and Ram voltage might work for you also. I'am at 1.6v MCP, 1.35 FSB and 2.175 for my Ram voltage. Bumping up these voltages made all the difference for me.