Asus' firmware has several overclocking modes, and the Z87I-Deluxe follows that theme. Selecting XMP overclocking mode before making other adjustments enables both XMP-memory and manual CPU overclocks simultaneously.
The Z87I-Deluxe properly selects the highest-functioning DDR3-2933 memory ratio for our Haswell-based processor, increasing BCLK to 102.3 MHz to enable its DDR3-3000 rating. We had to back it down to 100 MHz to find our CPU’s 4.6 GHz maximum frequency.
Heat is the reason our CPU tops out at 4.6 GHz, as core voltage levels greater than 1.25 V result in thermal throttling. We reached that limit at this motherboard's 1.245 V setting.
DRAM is even more aggressively over-volted; our voltmeter showed a 1.65 V output at the board’s 1.635 V setting.
Primary, secondary, and tertiary timings are adjustable. The top three settings switched from “Auto” to our memory’s XMP ratings when XMP mode was enabled.
Because the Haswell architecture's core voltage is internally regulated, we left load-line calibration settings at motherboard defaults.