“After a great many tests, in a large number of combinations, my machine appears to be stable with the following settings:
Raspberry Pi 3 Stable Overclock Values
Its all a bit hit and miss on the Pi3 I was using settings basically the same and I started to get corruption and now no boot, lucky I backed my Retropie setup before I started to play.
Before messing with the over clock on pi3 backup up first or use a old card for testing. It seems not as simple as with Pi2 and Pi1, this maybe why in the official overclock menu it says no overclock available.