Papervision is not an active 3d lib, for 60fps rendering you have to use a 3D hardware accelerated flash framework like one of those :
Away3d demo : http://away3d.com/showcase/
Flare3d demo : http://www.flare3d.com/showcase/
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Minko
demo : aerys.in/portfolio/mercedes-e500
Alternativa3D
demo : alternativaplatform.github.com/Alternativa3D/Demos/ParticlesDemo/
And yes they all works on an ipad :)