DirectX: AutoCAD 2013, 3D
We like to run 2D benchmarks for the sake of completeness, but 3D is where we expect to see most of the differences between these cards. After all, 3D performance is why you'd pay more for one high-end graphics board over another.
Summary of the 3D Performance Benchmarks
While all of the cards look pretty similar in our 2D test, the same can't be said for the 3D benchmark. Nvidia's GeForce GTX Titan pulls ahead of the 680 and 580. Meanwhile, two generations of AMD architectures are significantly slower. The 40 percent difference between the GeForce GTX Titan and Radeon HD 7970 put them in completely different leagues.
It's also pretty interesting that the GTX Titan, 680, and 580 aren't all that far apart from each other. If you already own one of those other two prior flagships, it's probably not worth sinking another $1,000 into the GK110-based board exclusively for AutoCAD.