I made a little test game with 35 sprites (24 x 24 pixels) with no complicated logic.

If I cap the framerate at 60fps, I get max 56-57fps.
If I cap the framerate at 120fps, I get 61-62fps.

I am testing on iphone 3gs.

Is there any explanation for this?

How exactly are you setting the framerate?

I dont see the problem ?
As most games on android and iphone run with an framerate around 30-60 fps.

Both android and iphone is locked with an 60 fps frame rate.

And if you then set an higher framerate so is it the hardware that locks it when its higher,and if you have an locked 60 fps framerate in your software so will you get an slightly lower framerate then 60.

I am just asking if this is a normal behaviour, as I am testing how various things work.

Setting fps with agk::SetSyncRate(60,0)

Most mobile devices seem to be locked to a maximum of 60fps. Making AppGameKit also lock the frame rate to 60fps introduces a sleep command every now and again to try to match 60fps which may not be very accurate. You can use the second parameter in agk::SetSyncRate(60,1) to make it busy wait (loop continuously using 100% CPU) instead which will be more accurate.

is the sleep command not accurate or the get fps command?

Sleep may be off in some cases, there is no requirement for the OS to wake up your app after the exact time that you gave it.

thanks for all info

I don't know about other platforms but for Zune and Windows Phone Microsoft reccomends 30fps for the sake of battery life. 60 seems like overkill on a mobile device but then again I guess a lot of iOS games sit about there.

30fps is too little for action games. for puzzle type and thinking games 30fps is fine