How to turn on turbobust, so that it works constantly at 3.4GHz?
It depends on the power management scheme chosen. (Control Panel \ All Control Panel Items \ Power Options)
In a simple way - you need to choose a scheme with high performance.
Or independently change the scheme, specifying in the section about "CPU power management" in the sub-item about "Minimum processor state" - 100%, and also 100% in "Maximum processor state".
In this case, the processor will always have to work at the maximum frequency, even in the absence of tasks. But this solution, it turns out, does not use the ideology embodied in TurboBust, which itself decides when to overclock the processor, and when it is possible to reduce the frequency.