http://www.techspot.com/review/1433-intel-core-i9-core-i7-skylake-x/page4.html
"Using just 1.2 volts, which is all I needed for a stable 4.6GHz overclock on all cores, the system consumption went from the 259 watts just seen to an insane 402 watts! That might not even be the worst part, the deal breaker is probably the operating temps. Chilling the 7900X was Corsair's H100i v2 and despite being a premium 240mm AIO liquid cooler, temps skyrocketed as the CPU was place under load, reaching 90 degrees instantly before climbing further towards 100 degrees. Unless you have an amazing cooler, I'm not sure overclocking is going to be worth it."