I've already OC'd to 4.5 with Asus' auto overclocking and jumped it up to 4.7(23.5x200) myself, but would like some help as to get it further. I don't have too much overclocking knowledge and would like some help from the Tek community to see what you have achieved on it.
Currently running on a M5A99X EVO 2.0, with a H110 cooling it. CPU Voltage is at 1.5.
CPU voltage shouldn't be that high with just 4.7GHz. 1.5v is about right for 4.8GHz to 4.9GHz.
Try 4.8Ghz at 1.45v then stress test with aida64 or something similar and if it is stable keep lowering voltage one increment at a time until it becomes unstable then revert back to last voltage. Also make sure temps are not getting too high. I try to keep mine under 60c but the CPU should still be good up to maybe 70c but that is really pushing it.
Try this Link
Both are asus boards so the principle stands, i second stressing with aida64, also agree with temps. Try to keep it under 60c, 65c at max for me. I've got 4.8@ 1.43v but silicon lottery, just look at that guide it should help.