How to Enable turbo boost ?

How to Enable intel turbo boost in the pve ?

What makes you think it isn't enabled?

Out of the box I have no issues with CPU's with Intel Turbo Boost from boosting as and when they can / required
 
What makes you think it isn't enabled?

Out of the box I have no issues with CPU's with Intel Turbo Boost from boosting as and when they can / required
The win7 and server2016 systems were installed in pve, and the cpu frequency was not changed during use
 
The win7 and server2016 systems were installed in pve, and the cpu frequency was not changed during use

Where was you looking to see the CPU Frequency change?

On the host node if you run "cat /proc/cpuinfo | grep "MHz""

You should see the CPU Frequeny change, if you run something demanding you should see the frequency ramp up if possible depending on the CPU and the amount of active cores.