SoundStorm
The SoundStorm audio system was one of the first consumer computer audio products to offer real time Dolby Digital 5.1 encoding. This meant that one could play games or music and output them as a 5.1 stream digitally to an external decoding speaker system. This solves a common problem with most digital sound solutions of having to hook up both digital and analog connections at the same time so you can have surround sound in both games (using the analog connections) and movies (using the digital connection). Only recently has Dolby Digital live allowed competitors such as Creative's x-fi line up to offer real time DD 5.1 encoding.
Some see the passing of SoundStorm as a classic example of the bottom dollar approach to building computers sweeping the PC industry, with component quality being gradually eroded, in favor of pricing considerations. SoundStorm was good competition for Creative Labs during its time, but did suffer from driver issues and performance problems. Many computer owners also had their own discrete audio solutions, such as the popular Creative Audigy series, the VIA Envy24, or various Turtle Beach boards, among other high end solutions offering superior analog quality. This made the NVAPU/SoundStorm a niche product in a market where keeping board costs low is essential to sales volume.
SoundStorm/NVAPU's existence was a direct result of Xbox development, with the APU being directly related to the technology used in Microsoft's console. As the technology aged and consumers and OEMs showed a lack of interest in purchasing the more expensive but higher quality chipsets, Nvidia did not see reason to justify further R&D expenditures.
Read more about this topic: NForce2