no on 3DFX-I and 3DFX-II and similar cards the limit was 256x256 - there was no limit imposed by DBC and neither is there by DBPro.
The limiting size of a texture is not DB, but the graphics card that the .exe is being run on. Some have a maximum total dimension and some insist on square textures, the bigger you go the more likely you are to exclude older cards.
512x512 is considered by many to be an accepteable texture size that works on most cards.
It would be very nice if DB terrains/matrixes supported multi-texturing and multiple texture images. Until they revise the landscaping tools in patch 5-6 or 7, we'll just have to stick it out with matrixes.
Pneumatic Dryll, Outrageous epic cleric of EQ/Xev
God made the world in 7 days, but we're still waiting for the patch.