DirectX 3.0 introduces several technical features not present or as refined in version 2.0: Screen Space Reflections (SSR): High-quality reflections on wet surfaces and vehicles. Volumetric Clouds & GodRays:
Despite the massive visual jump, DirectX 3.0 is surprisingly well-optimized. It utilizes modern GPU architectures more efficiently than older DX9 wrappers, meaning you get more frames per second (FPS) for the level of fidelity provided. How to Install for Maximum Stability