The DSP on the APU was normally driven by code largely derived from the 3D audio middleware company Sensaura. The Sensaura middleware was also used by the Windows drivers of nearly every sound card and audio codec other than those by Creative. Unlike the usual software implementations of the Sensaura code, the SoundStorm solution ran the same code on a hardware DSP, which resulted in extremely low CPU usage. It was also capable of realtime Dolby Digital 5.1 encoding. Compared to other audio solutions of the day, the difference in CPU usage when running popular multimedia applications was as much as 10-20%. While the Audigy offers similar performance, it does so at a much higher price point, and only as a discrete add-in solution.