Wireframe speed

I realize that that I may be beating a dead horse here, but why in god’s name does the GeForce2 take as much as a 50% performance hit when rendering in wireframe instead of polygon’s. I have an app that calls glutWireTorus a few times inside a display list. That display list is only initialized once. When I run the program, it goes about 50% faster if the tori are rendered versus when they are not. This is unacceptable. Can anyone from NVIDIA explain to me why this is so? There may be a good reason for it, but right now I’m not seeing it.


[This message has been edited by Tone (edited 03-13-2001).]

nVidia has said their consumer hardware is slower at drawing lines than at drawing textured polygons. That’s just a design decision they made. We have to live with it, or buy another card, I guess.

If you think of a line as a very thin polygon, it makes sense, because there’s two rendered triangles per line, and three lines per triangle you give to OpenGL. I don’t know if that’s how they implemented it, however.

I just found this out too … In FILL mode I get 1400 FPS, in LINE mode I get 100 FPS! In POINT mode I get 97 . These tests were on a GeForce2. On a GeForce DDR I get 1050 FPS in FILL mode, 500 FPS in LINE mode and 500 in POINT model. Go figure. My Voodoo3 runs LINE mode at 250 FPS.

There’s a reason for this…

If you really need the quick wireframe rate, and you’d rather not purchase a Quadro…

Do this… http://www.geocities.com/tnaw_xtennis/

change your geforce into a Quadro…

The reasons behind this where discussed on the OpenGL-GAMEDEV lists a few months ago.

-akbar A.

This is where profesional gfx boards come in, they have a far faster geometry engine but a slower fillrate than consumer boards (except quadro’s which are basicly overpriced consumer boards, sorry NV ).