Why is it that afx 5.0 is slower than 4.1, specially on the previews? I have found that turning the audio off helps, but is still slower... also having over 400Mb of ram assigned to afx 5.0 makes it worse.... 300mb works better...
the more ram you have the longer it takes aftereffects
to reorder that ram and preview it, so you can render
a preview to ram on a computer with less ram and it will render faster, but if you have more ram it takes longer to reorder all that ram but you will ba able to render longer
previews. hope this helps