Rampage IV Extreme Firmware Overclocking
The Rampage IV Extreme OC Tweaker menu gets slightly expanded from the already well-populated versions of Asus’ other high-end boards, including four built-in overclocking profiles at 4.375, 4.70, and 4.985 GHz. Additional screenshots are available in our photo album by clicking on any of the below images.
The voltage levels for “Extreme” profiles are a little too aggressive for our tastes, since we prefer our processors to survive though several of these experiments. Yet, rather than chose our traditional long-term-safety levels, we stepped up our game to a marginally-safe 1.45 V.
Our maximum stable overclock was 4.86 GHz, using a 101.3 MHz base clock and 48x multiplier. Our target 1.45 V core came at the Rampage IV Extreme’s 1.40 V setting.
CPU ratio control and power safety limits are found under the CPU Performance Settings submenu. Asus states that Auto is optimal for most users, and we experienced no restarts when using it.
Per-channel timing controls lead to an extra-long DRAM timing control menu. Our memory’s XMP register made configuration simple.
The DIGI+ Power Control offers droop control (among other things) in the form of the CPU Load-line Calibration function. We found that the High setting kept our CPU core very close to its original voltage level under a variety of test conditions.
Various additional signal controls are found under the Rampage IV Extreme’s CPU, Memory, Chipset, and VGA Tweaker’s Paradise submenus.
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! ;)