The gspTurbo3D microcode is a feature-limited, precision-reduced, optimized version of the 3D polygon microcode. It uses a completely different display list organization that is more efficient, but less general.
Because of the reduced precision, the turbo microcode is not suitable for drawing backgrounds or objects with precise textures. It is designed to draw "characters" objects that generally remain in the middle of the viewing frustum.
The following features are not supported with the turbo microcode:
Applications are responsible for the decision whether objects are visible or not by the drawing order since clipping is not supported.
Current performance measurements of this microcode are about 5K polygons per frame @ 60 Hz without using Z-buffer at all. For more information, consult the man page for gspTurbo3D(). Also, quality of graphics and the number of displayed polygon can be checked with the sample program, turbomonkey which the Turbo3D microcode is used in.
This microcode is in it's first release and may change.