Gigabyte still uses its familiar high-resolution GUI for firmware settings, but a press of the F6 key allows us to zoom.
Frequency, Memory, and Voltage get separate tabs, where the Frequency tab controls base clock, CPU core, integrated GPU, and DRAM ratios. Though our CPU reached the same 4.59 GHz frequency as Asus' competing Maximus VI Formula, our DRAM was only stable up to DDR3-2800. Since Haswell’s maximum functional ratio gives us DDR3-2933 at a stock base clock, the board would have automatically added 2.3 MHz to the CPU base clock.
All multiplier-based overclocking relies on Intel's Turbo Boost functionality, though disabling Turbo Boost allows the Z87X-UD5H to lock a fixed multiplier ratio and turn off certain power-saving features. Other power settings must be manually configured to completely lock-in a specific voltage.
DRAM timings can be configured as all-channels (Manual) or in per-channel (advanced manual) mode. Memory profile and ratio settings are repeated from the frequency menu.
Each timing can be individually selected without disabling automatic mode for other timings.
Gigabyte loves submenus, so we need to jump through several pages to set up our basic overclocking parameters. Beyond those, we could also alter voltage droop compensation, power, and thermal limits through the Z87X-UD5H Advanced Power Settings menu.
Three more pages of submenus give us CPU, DRAM, and PCH voltage control. We had to select 1.23 V to reach an actual 1.25 V core at or near idle, and core voltage still climbed to around 1.268 V under load. Higher voltage settings allowed the maximum core voltage to climb to a thermally-triggered throttle-inducing 1.27x volts. Similarly, a 1.635 V DRAM setting took us a few millivolts past our actual 1.65 V target. Actual voltage levels were verified with a voltmeter.