P-dye: Old TY certified for 16X or less writespeed.
DX-dye: Newer TY type certified for 24X or better.
Notice that BoSkin is talking about old discs (P-dye is most likely d-view 12X certified, while the other reflex ultra discs is probebly 24X certified). Am I right BoSkin?
NOVA - If you was thinking of the difference between newer discs than this, please tell