Power And Heat
We performed all tests using Automatic as our primary choice and Enabled as our secondary choice for every power-oriented option, and this revealed something about the Asus Rampage IV Extreme:
Unlike most motherboards, the Rampage IV Extreme appears to automatically disable certain power-saving options. Our third choice would have been to force everything on, but our primary concern in today’s comparison is overclocked performance where these features are disabled anyway.
The X79 FTW’s voltage regulator heat sink appears slightly less effective than its competitor’s. But then again, we're using a liquid cooler with a low-speed SFF21D fan over the motherboard. Stronger airflow would help the board survive under greater overclocking extremes.
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! ;)