When changing Vid Cards, what does one do in software?
 

Simply unplugged the old gefource4 440MX, and plugged in the ti4200. Is there anything to do in software?

glx gears seems to run a little slower than I would expect (~3500/FPS). The xorg.conf still say 440MX, but is that just residue?

you do need to update /etc/X11/xorg.conf to reflect your new graphics/video card...