ASRock Z77 Extreme 4 Review @ OCC
 

When it came time to overclock with ASRock's E77 Extreme 4, I was pleasantly surprised to see that it could pull off the same overclocks as some if the high end boards I have used. It easily delivered a nice 1.2GHz overclock on my Core i7 3770K without any real voltage challenges, with the use of ASRock's Digi Power VRM design and 8+4phase power circuit. Overclocking via AXTU was uneventful in that the utility worked to allow overclocking from within the operating system. Where I had some concerns was with the inability to run my test system memory at its native 2133MHz or even as low as 2000MHz. Voltages, timings, and the latest BIOS did not alleviate the problem. I understand memory incompatibilities and see them from time to time, but with plenty of modules with similar specifications and memory ICs on the QVL list, it is still a surprise. Other than that small hiccup, the board delivered performance to go with its good looks.

http://www.overclockersclub.com/revi...z77_extreme_4/