Rampage IV Extreme Software Overclocking
Asus TurboV EVO includes three overclocking profiles in addition to a fairly extensive set of manual controls. The highest of these Level Up profiles sets a modest 1.27 V CPU core.
Manual controls include CPU base clock frequency, CPU ratio, CPU base clock ratio, CPU core and DRAM voltage, and various interface voltages for the chipset and memory controller.
Many of those settings require a reboot to work properly, though the program itself does not impose this requirement. As such, changing the BCLK and clock strap from 125 to 100 MHz, for example, caused the system to lock, even though it’s a frequency reduction.
Asus Digi+ power controls are also present in software, including the often-needed Load-line Calibration setting that reduces voltage droop at full CPU load.
Asus Fan Xpert lets users set a custom fan speed curve based on component temperatures.
Where is the MSI Big Bang Xpower II? That's known to be a great board for overclocking as well.
Just knowing the ASUS and EVGA from past history (LGA 1366) which may or may not play any role here, ASUS tends to (lets call it adjust) the CPU vCore and VTT/VCCSA higher than advertised vs EVGA which probably explains* the problems with both the high frequency RAM and CPU OC's.
The disturbing thing to 'me' was the regulator voltages. I know the EVGA uses 12+2 vs ASUS's 8+3+(2+2) PWM and it's all digital controlled on ASUS, (*)but IDK if the EVGA is digitally controlled which might explain the inefficiency and OC.
The EVGA has always been a very 'manual' MOBO, so in that regard I'm not surprised you had to dive into the BIOS. I have no doubts if you raised the EVGA's voltages vs a cloned ASUS optimized OC set that you'd have no problems obtaining the SAME 4.8GHz OC. Both boards offer voltage check points and I'd be very interesting how they compared.
Just the other day I updated my ASUS BIOS and right-off I noticed an increased vCore increase by +0.01v~+0.015v and as part of the documented (improvements) was 'Improved Stability' ; yeah sure if you raise the vCore or VTT/VCCSA, phase, etc profiles... Now I have to redo my validations.
The most important testing here, to me, is the Baseline Comparison which tells me EVGA has some work to do ASAP, and hopefully a BIOS update can close the gaps. Further, personally I won't buy or recommend any X79 MOBO unless it offers an 8xDIMM option. In the forum it's been very clear which X79's I recommend since day one, and the ASUS R4E has always been on top on my list if you can afford it! ;)