oh, it can quite easily have an effect on all production. it could simply be a multiplier (default = 1.0). However, it doesn't seem to be the case. So i'm wondering if it has another effect and whether anyone out there has discovered what it is.
When it says = 1.0 it means the %age increases by one if you put = 2.0 then it will go up by 2's, but it still takes the same amount of time to build everything.
It will double the build speed, but technically the object is building in the same amount of time, just think of it as someone pressing the Fast Forward button on the VCR or DVD player.