Many years ago sound cards were almost completely replaced by integrated solutions that offload the sound processing to the CPU. The Inquirer heard at Intel's latest IDF that the firm is preparing a major shift for generic PC audio by offloading the audio to a DSP to save power.
The main reason for this is to improve the battery life on mobile systems as a dedicated DSP chip can perform this task much more efficiently than a CPU.
Instead of consuming a 20 per cent chunk of a 130 W CPU, all that sound stuff could be done even better and faster by a less than half watt audio DSP! With the current integration levels, it can simply be embedded in the current footprint of that 'software assisted' audio codec chip on most mainstream mobos.
Any excessive power usage problem hits the notebooks first, of course. An Intel presentation stated that a combination of Vista and new hi-fi audio formats increases audio power consumption by as much as 500 per cent. It even grabs an extra 4 W during movie playback and can go even higher. This is large enough delta to impact the battery life - up to extra 30 minutes according to Intel.
That huge saving could be realised not just because of the nominal watts difference, but also because the real-time nature of software audio, with its millisecond-frequent interrupts which prevent the CPU from dozing off into the lower power states, even if there's nothing else to do. The HD Audio Link 20 microsecond DMA prevents entering the lower power chipset and memory states, too.