I have bought an energy meter today and CPU benchmarked BMW27.blend on two different systems.
The results really surprised me, since the gap is so big.
GPUs were used for display only.
AMD Phenom II X6 1100T
Dual Intel Xeon E5 V4 ES 2.0 Ghz
Nvidia GTX 470
Nvidia GTX 1070
System power consumption at idle
64 W – 115 W
System power consumption at load
Damn. That’s about 8.15 fold efficieny difference.
Also note that the Intel CPUs are ES (engineering samples), which means they are a bit less efficient than official versions.