Benchmarks: Power Consumption
You may wonder why the power consumption is so much higher than the Core i7-4770K's. Our investigation found that the engineering sample Devil's Canyon chip would auto-default to 1.152V in the BIOS, compared to 1.08V for the retail Core i7-4770K. A combination of higher frequencies and higher voltage increases system-wide power consumption by over 20 per cent. The chip needed all of this voltage, too, as it wasn't stable when we manually inputted 1.1V.
Do bear in mind that voltage is chip specific; some will run with lower power consumption, others with higher. Intel is probably estimating that voltages, on average, are likely to be the same as the 4770K, and it's only the increase in frequency, rather than voltage, that requires TDP to be raised from 84W to 88W.
The additional voltage also plays a part in increasing the power consumption when running games. But thinking about it logically, 80W isn't going to stress any mainstream PSU in the slightest.
A word or two about temperatures: Intel says it is to use the same processor-in-box (PIB) cooler for this chip as for the 4770K. We used just such a heatsink during regular testing and found that, due to the extra power consumption generated by higher voltages, the Core i7-4790K ran hotter, at an average of 88C, compared to 78C for the older Haswell processor.
