Power & Temperatures
Out of the box, the 1700X consumes a similar amount of power as the 5960X while the 1800X is quite a bit hungrier. The total system consumption for the overclocked 1700X was 220 watts, or nearly a 30% increase in power draw for what was up to a 10% boost in performance. The overclocked 1800X pushed total system consumption up by almost 20% to 284 watts.
For some reason, the Ryzen processors consume maximum power in Excel test whereas the Intel processors don't. Therefore, comparing power consumption using Prime95 gives more balanced results and makes the 1700X and 1800X look considerably more efficient. Here the stock 1800X consumed slightly less power than the 6900K while the 1700X was similar to that of the 6800K and older 4790K.
Operating Temperatures
I saw respectable temperatures on the Ryzen 7 1800X processor using the supplied Noctua NH-U12E SE-AM4 cooler. The chip idled at just 35 degrees and peaked at just 53 degrees under full load using the AIDA64 burn-in test. At first I thought the motherboard or software must have been reporting incorrectly but after 40 minutes of load the heatsink was barely warm to touch. Testing was conducted with an ambient room temperature of 21 degrees.