What does performance mode do?

[Blastboom Strice]

May I ask, what does the new performance mode do? Is it overclocking the cpus/gpus/ram etc.? Is it (very) bad for the device (like, do the voltage and temp rise higher than they should)? Before it was unlocked, were the devices running in "balanced mode"?

PS. I see that this probably was a feature of older miui versions.

 

[Blastboom Strice]

Update: Hm, so apparently it allows the cpu to run faster, as I can see that the fastest core's max frequency goes from 2.745mhz goes to 2.841mhz. Does it do anything else?