We used the BIOSTAR TZ77XE4 to overclock the processor Core i5-3570K. In our tests, the Core i5-3570K Retail is capable of doing 4.5GHz on AIR with RAM running at DDR3-2133 C10-12-10-1T. If you were to compare to previous generation Core i5-2500K, the Core i5-3570K seems to underperform by 100-200MHz.(we can overclock a Core i5-2500K on AIR to 4.6-4.7GHz easily). Below is a screen shot of our test.

Kingston DDR3-2400 modules were used.

CPU voltage 1.20v, DRAM 1.668v, PCH 1.116v, Vcc 1.116v

Full review of the BIOSTAR TZ77XE4 motherboard can be found here.