Since DragonFly has been diverging from the FreeBSD 4 model, and because NVIDIA no longer produces a FreeBSD 4 X11 driver, there is no 3D acceleration for NVIDIA chipset video cards under DragonFly. It’s frustrating, though there are efforts to deal with this.
Looking at the latest version of xorg, there is mention in a few places of 3D support for more recent ATI cards, though it’s not reflected in the radeon man page.
I already wrote nvidia on the subject.
Tell us the right email address and we can try to overwhelm them with numbers :)