expletive said:
I agree, so wouldnt it mean that its minimum framerate is over 60fps
Not necessarily.
A couple frames here and there below a rate of 60fps is not going to be a deal breaker. The problem is when you spend a significant amount of time jumping from 30fps to 60fps. In my experience, and of that of a lot of people I know (and also of the game reviewers I trust), the general consensus is that a game locked at 30fps is more fluid and appears more stable than a game that constantly "hiccups" and drops frames and bounces from 60-to-30-to-60-to-30 etc. A jumpy game, although it averages a higher frame rate, appears choppier than a solid 30fps to many people.
But a few drops are not very noticable in most cases.
So your minimum framerate in any given sample is most likely going to be below 60fps, even if your average is well above 60fps.
Take Doom3 on the 7800GTX. Even capped at 60fps you can see the game drop a bit below 60fps. Even an SLI rig does. (Note in that link the average FPS is lower than 60fps because of the cap; if there were no cap the average would be well above 60fps, but the drops would still occur).
Of course Doom 3 on a 7800GTX or 7800GTX SLI is very smooth, even if it drops some frames. The key is limiting the number of drops. The higher the number of drops the greater chance you will begin to "annoy" someone or they will notice.
This is one reason on the PC I prefer, graphically, games that are either very stable OR setting the resolutions/features for a game on my video card in a situation where the drops are not as noticable. e.g. Playing BF2 and seeing the framerate drop to the 20s when I am averaging above 60fps is REALLY annoying. An average of 60fps is usually just not enough if there are big jumps so settings that bring the framerate in the 80s (or a better GPU!
) really make things a lot nicer!
Some drops are ok, but the constant jumps are very annoying in any game. I am not sure there are any hard and fast rules on what works and what does not. I think most developers would eye ball it and test it and go with what works best at the end of the day based on impression from the dev team and testers.