Exactly. So if there were 30 frames rendered it won’t tell you the relative speeds at which they were actually rendered and there can be considerable variation in those speeds which you won’t see.
@Andrew_Stacey So it gives you the exact amount of frames rendered in the last second, right?
(Which is what people think of when they say FPS)
@SkyTheCoder That’s what I mean when I say that it is a very literal interpretation of FPS. What people think of when they say FPS is something that only they know. What people should think of when they say FPS is something better known as frame rate. This is measured in frames-per-second but is not literally “count the number of frames in every whole second”. By analogy, the speed of a car in expressed in miles-per-hour or kilometers-per-hour (mph or kph), but we don’t measure it by driving for a whole hour and then seeing how far we’ve gone. Rather, we measure how far we go over a short period of time and then scale up to get the number of miles we would go in an hour if we continued at the same rate.
So although your measurement is literally accurate, it is only so because we’ve been conflating the unit of measurement (frames-per-second) with the actual quantity that we are measuring (frame rate). Obviously, this has confused you (and probably several others) and so we should be more careful to be precise in future.