triple buffering

[roudoudou]

in a demo, lag has no meaning

in a game...

that's why emulator authors try to reduce lag...

...sometimes

[McArti0]

In Jet planes you always have a lot of lag. So it must be Jet simulator games. 

[Anthony Flack]

Any kind of screen buffering on the GX is also complicated by the hardware sprites, which will have to have their data buffered as well, or else they'll get ahead of everything. But a sprite game on the GX should rightly be aiming to hit 50fps anyway.