It isn't always obvious that you should use hardware over software renderers. Software renderers work with small polygons efficiently but are not so adept at working with big ones. They use the monochromatic model rather than the RGB model. Hardware renderers, on the other hand, are good at big polygons but less good at small ones. They use the RGB model instead of the monochromatic model. Even if you use hardware, the transformation and lighting are likely to be in software, so CPU speed is still critical to excellent performance.