What does the Ultimate Performance power plan do?

[TheBiggestOfBuschemis]

What exactly does it do? Is it in any way beneficial?

[Mira Yurizaki]

It's likely disabling a feature in Windows' scheduler that clumps up timeouts to the next time the scheduler polls for timeouts.

 

Basically an app can set a timeout (i.e., it's going to wait a certain amount of time) when it knows it has to wait for something and it lets the OS know the app is idling. When you have many apps all working at different things on different times, they can create a chain of timeouts where the OS will idle, then service a timeout, and it never gets to idle long enough for the system to be considered really idling. This can cause the average power consumption to be higher. So what Microsoft did was it could delay servicing an app timeout so that multiple apps can be serviced at once. That way, the OS can idle for longer and let the hardware go into lower power states.

 

The problem with this is that transitioning between power states incurs a latency penalty in execution. The processor cannot do anything useful while it's transitioning to a higher power state because things have to ramp up or turn on.

 

Also on top of that, it could just be letting the OS not have hardware go into lower power states. It's always in the highest power state.