Z87 Extreme6 Firmware
Though everything can potentially be configured manually, the easiest way to overclock your Haswell-based CPU from Extreme6's firmware is to pick the pre-defined clock that’s closest to your desired settings, and then make minor changes. Built-in configurations up to 4.8 GHz at 1.42 V were initially stable with our CPU, though thermal throttling forced us to seek lower values.
Starting with the "Turbo 4.4GHz" profile, I was thrilled to achieve 4.6 GHz through a simple multiplier increase. Then again, this was the first board I tested.
Our test memory’s DDR3-3000 XMP setting almost worked, but the Z87 Extreme6 firmware doesn’t appear to know the multiplier limits of Intel’s memory controller. The memory is supposed to operate at the DDR3-2933 ratio with a slightly elevated base clock, but I had to manually set its multiplier.
The Z87 Extreme6 also surprised us by adding 60 mV to our DRAM voltage setting, and then misreporting the actual voltage. Our volt meter revealed that 1.65 V actually occurs at the 1.59 V setting, and that the 1.59 V monitored value is simply inaccurate.
Primary, secondary, and tertiary timing controls are all available for full tuning, and each item can be separately changed from automatic to manual configuration.