Here's the story behind it
Developed collaboratively between Nvidia and Sega, the 1MB Diamond Edge 3D shipped in 1995 for $249.99 with an adapter board that plugged into the graphics card that added two Sega Saturn controllers ports. The bundled games included Saturn titles such as Virtua Fighter Remix and Panzer Dragoon, which were ported to Windows 95.
Like an actual Saturn, the Diamond Edge 3D rendered graphics via quadratic texture mapping instead of using triangles or polygons. The graphics portion of the Diamond Edge 3D was handled by Nvidia's 60MHz NV1 chipset (manufactured by SGS-Thomson as the STG2000), while the integrated MIDI audio engine offered 32-channel, 350 MIPS playback-only capabilities.
The combo package proved unpopular among PC builders at the time, who found better performance and value in buying separate graphics accelerators (ATI Rage, Rendition Verite, among others) and sound cards. An actual Sega Saturn controller was not part of the bundle initially but was later added to sweeten the deal to no avail.
Nvidia's next effort would be much more successful in the form of the RIVA 128 (Real-time Interactive Video and Animation), designed as a triangle polygon-based 3D accelerator supported by Direct3D and OpenGL APIs. It was built on the 350 nm fabrication process and clocked at 100 MHz.