I think the dos benchmark you are looking for is called Doom bench.
Talking of Rendition optimised games, I found a copy of Hexen 2 in a drawer recently. Found that if I renamed the opengl dll that it came with then it ran fine in 3Dfx VooDoo mode (which is what I had at the time). The VooDoo GL stub may have been limited, but that really makes you appreciate standards.
Hours of fun catapulting sheep etc