I need some clarification on Intel Turboboost

Dammit, Linus! According to this video, Turboboost frequency affects only one core? That makes me want to ditch my i5 6400 and go for the 6500. I thought the idea of having something run at 2.7GHz base clock is AWESOME when not under a lot of load. And boosting up to 3.3GHz when the power was needed sounded really sweet. Then when i heard that only one of the core can boost to that amount, it really turned me away. I thought the processor as a whole goes up to that amount when the power is needed... Or is this untrue?

for single threaded applications it turbo boosts one core if the cpu is cool enough. but for multi-threaded applications all the cores will turbo boost, if the cpu is cool enough.

Ah... Hmm... Well, i wonder in the case of the Skylake i5's, what's considered cool enough?

~50C - 65C depending on the cpu