If you are using the Stock HSF, Intel HSF is at the bottom of the Totom Pole in terms of performance. Run prime 95 to verify your OC is stable MONITOR your temps.
Have the ASrock Extreme 4, w/i5-2500K. My asrock had a utility and all I did was set to 4.2 and walla,reboot and 4.2
I have a hyper 212+ push/pull getting a max of 48-50C at 4Ghz. Thanks for all, but when I tried to disable the power saving features it wasn't stable.