I made a comparison between P9X79 Deluxe and Rampage IV Black Edition. I used the same BIOS settings for E5-1680V2 on both motherboards: Vcore - 1.27V, CPU Load-line calibration - High.
It seems that P9X79 Deluxe has no VRM sensor, while Rampage IV Black Edition VRM sensors are probably detected by Hwinfo as Temp2, Temp3, Temp4, Temp5.
Note the discrepancy between CPU Core in AIDA64/Core Voltage in CPU-Z/VCCIN in HWiNFO64 and CPU VID in AIDA64/Core VID in HWiNFO64.
Rampage IV Black Edition during idle.
View attachment 227813View attachment 227814
Rampage IV Black Edition at load.
View attachment 227815View attachment 227816
Note the discrepancy between CPU Core in AIDA64/Core Voltage in CPU-Z/Vcore in HWiNFO64 and CPU VID in AIDA64/Core VID in HWiNFO64 is even higher than on Rampage IV Black Edition.
P9X79 Deluxe during idle.
View attachment 227817View attachment 227819
P9X79 Deluxe at load.
View attachment 227820View attachment 227822
So which one seems better to you?