When I use a overclocked machine the time left till a piece of coal is macerated or water cell compressed is not accurate.
The white bit does go faster, But with more overclockers the white bar doesnt fill all the way up before suddenly "finishing" the job and starting the next piece.
With 3 overclockers, Its approx 3/5ths of the way before it decides it finishes and starts the next.
This isnt a server lag issue, Something like the server thinks the overclocker is 2x more powerful then it really is. And the client doesnt know this.