It's X vs 1/X. If it's 1/X of time, you get properties such as something that is twice as fast is a 0.5 times the value, but something 4 times as fast is only .

It's X vs 1/X. If it's 1/X of time, you get properties such as something that is twice as fast is a 0.5 times the value, but something 4 times as fast is only .25 times the value. thus making the result non-linear. Also I think something that makes it a bit more clear the advantages of being time/ops consider optimizing a video game, and we have the task of trying to get from 60 FPS to 90 FPS and we have say 10 sub tasks that each take say 10% of the frame time, it's hard to say how much optimization I'll have to do off the top of your head. But if instead I say that you have to get from a 16.6 ms frame to an 11.1 ms frame, and you have 10 tasks that take 10% of the frame time, which is obviously about 1.66 ms each, and I also know I need to save 5.5 ms of frame, the scales of which I'm thinking in are all nice and easy to reason about.