The gpu is trying very hard to balance the FPS around the desired value...
and it's a really a hell of job to do it right: some frames will be very fast
(for example an average of 200 fps), because there will be drawn nothing in it.
Other frames will be, because of drawing/texture uploading, maybe at 30 FPS average.
So the gpu is measuring the average speed of the last 10 frames and tries
to slow things down, if it's to fast... and now, with the slowed updates the timing
will be different again... not easy... dunno if I can improve that any further
In real gameplay you will usually not notice anything if the speed is going down
somewhat... but in mdecs the main emu also fires up XA data to the spu plugins,
which are very sensitive if speed is too fast or too slow... depends how the spu
is coded as well, though.
Ah, well... at least I don't have any problems to get a constant FPS on my system
