Cpu running at more Mhz.

[Nightwish]

I've just installed a I7 8700k but when I checked the performance in task manager it was reading 4.5mhz (not 3.7). I know it has a turbo to 4.7, but would it use it if the PC is idle?

 

[Tolis_GR]

Yes. Turbo kicks in all the time. The load is spread all over different threads. Some threads will turbo and some others will run slower to help with effeciency

 

[Nightwish]

I thought the turbo kicked in when it was needed, not all the time. If its gonna run at 4.5 mhz all the time then they may as well sold it as a 4.5 mhz not a 3.7mhz.

 

[Tolis_GR]

Turbo boost is optional. You can disable it in bios settings. "When needed". If the processor can turbo only 1 or 2 cores and idle the rest of them, that is way more efficient than running all cores at base clock. This is how Intel sets up power efficiency.