Re: Help needed, TDFX [Re: Release-critical Bugreport for March 23, 2001]

[Juliusz Chroboczek <jch@pps.jussieu.fr>]

GS> You mean to say a Voodoo2 graphics card that is sold/marketed/used as a
GS> 3D only chipset, can be used under X4 as a '2D' card? With no other
GS> VESA/VGA card available?

Yep.  It's a ``shadowfb'' driver: all rendering is done in software to
a ``shadow framebuffer'', and the updated area of the shadowfb is
periodically blitted to the video card.

On a typical PCI setup, a shadowfb driver is roughly fourfold faster
than a plain unaccelerated driver because rendering operations don't
need to cross the bus.  (Advice to all users of the fbdev driver: add
``option "shadowfb"'' to your device section.)

GS> If the above is true, could you provide some pointers? All the material
GS> I've been able to find about V2 is mostly 'how to get quake/doom/etc to
GS> run on your V2 card and linux'.

Man 4 glide?

                                        Juliusz