NVIDIA TechDemo X-Isle on GeForce 256 DDR

X-Isle Benchmark V1.02 is (C) 2000 Crytek Studios
X-Isle was released as tech demo for Geforce256 and Geforce 2. It shows the cutting edge feature of CryENGINE.
Recommended hardware is a Geforce2, Pentium II 333 MHz, 64 MB RAM.
Though, the demo also runs on Geforce256 with a lower performance.
The scenes compare:
- texturing with vertex lighting
- bumpmapping with per pixel lighting
- environment cubemapping in refraction mode
- environment cubemapping in reflection mode
The video was captured from a Pentium III 800 MHz, Gigabyte GA-6BXU, 256 MB RAM, ASUS Geforce V6800 DDR (GeForce 256), Win98SE, Detonator 12.90, with default settings 1024x768 16bit color depth, VSync Off.
The demo shows the current number of polygons rendered, current fps and some more statistics. Noticably the GeForce 256 performance drops rapidly as soon as the dinosaur with cube mapped environment mapping is shown.
The Geforce256 specs are:
Chipset: NV10 (Celsius) at 120 MHz, 220 nm
RAM: 32MB DDR SGRAM at 150 MHz, 128 bit bus
AGP 4x, Direct3D 7
Programming: Vladimir Kajalin
3d models: Andrew Dorr, Olli-Pekka Saastamoinen
Artwork: Timo Kujansuu

[@SianaGearz]

Slow Chromosaurus. I wonder what causes it specifically? Do they have to compute all vertices for that one on the CPU? OpenGL supports accelerated generation of texture coordinates, but i don't know whether d3d7 has that capability. Is it an indirect blit roundtrip issue to create the environment map texture?

[@MichaelHuth]

I think that the main reason is that the GeForce 256 has a single texture mapping unit per pixel pipeline. I will capture another run with a Geforce 2 GTS that has two texture mapping units per pixel pipeline. This should really give a difference for the environment mapped scenes.

[@SianaGearz]

@@MichaelHuth I'd like to suggest that it's not a multitexturing fillrate issue. Since the issue with exceptionally low framerate is disproportionate to pixel count, and occurs any time the chrome guy is in view, even at a great distance.
Furthermore this effect is usualy single textured, looks like it here as well.
Some more fundamental feature difference between GPU generations, perhaps.

[@MichaelHuth]

@@SianaGearz Hmm, I think you are right.