GeForce 3 Series - Programmable Shaders and New Features

Programmable Shaders and New Features

Introduced three months after NVIDIA acquired 3dfx and marketed as the nFinite FX Engine, the GeForce 3 was the first Microsoft Direct3D 8.0 compliant 3D-card. Its programmable shader architecture enabled applications to execute custom visual effects programs in Microsoft Shader language 1.1. With respect to pure pixel and texel throughput, the GeForce 3 has four pixel pipelines which each can sample two textures per clock. This is the same configuration as GeForce 2 (not MX).

To take better advantage of available memory performance, the GeForce 3 has a hardware memory manager dubbed Lightspeed Memory Architecture (LMA). This is composed of several mechanisms that reduce overdraw, conserve memory bandwidth by compressing the z-buffer (depth buffer) and better manage the memory bus.

Other architectural changes include improvements to anti-aliasing functionality. Previous GeForce chips could perform only super-sampled anti-aliasing, a demanding process that renders the image at a large size internally and then scales it down to the end output resolution. GeForce 3 adds multi-sampling and Quincunx anti-aliasing methods, both of which perform significantly better. Finally, the GeForce 3's texture sampling units were upgraded to support 8-tap anisotropic filtering, compared to the previous limit of 2-tap with GeForce 2. With 8-tap anisotropic filtering enabled, distant textures can be noticeably sharper.