If you have overclocked an Intel processor on an ASRock board then this will not be much different, if any at all. By the time I had this board on test I had a fairly good feel for what the rest of my components could handle, most importantly my 5820K.
On previous boards, I was able to get my 5820K up to 4.3GHz @ 1.252V so this is where I started. I then went to up the multiplier, even giving it a bit more voltage and couldn’t get anything above 4.3GHz that felt stable. Next up was to see if I could the voltage any lower, and I managed to though not much. At one point I had the voltage at 1.225 and for some reason is just didn’t feel quite stable to me, it would boot into windows and pass all benchmark/stress tests but it didn’t feel right. It almost seemed as if sometimes when I went to open a folder or program it would take a bit longer than normal, when upping the voltage to 1.238V I would no longer notice this issue. Whether it was just me being paranoid or not is a hard call but at the end of the day 1.238V is where I felt comfortable.