Integrated sound hasn’t received much attention until recently. It simply existed, and that was all. It was one of the items in the mainboard features list and hence was viewed as such. However, the integrated audio subsystem has been steadily evolving and pushing out of the market all entry-level sound cards. Now, it is approaching even professional products.
Some prophets are already trumpeting the imminent death of all add-in sound cards as a genus, pointing at the sound solution from NVIDIA. But while NVIDIA is a direct competitor to the dominant force of the consumer market, which is of course Creative, VIA Technologies with its improved mainboard controller, Envy24PT, aspires for the professional market sector (I could remind you that the previous version of this controller – ICE1712 – appeared in a number of low-end professional cards).
Integrated sound is attacking; you can see this with a naked eye. So, this article is going to describe the combatants and pit them against each other!
Intel’s Endorsement: Where Did It All Spring Up From?
In the beginning was ISA. ISA begat PCI and died soon after. With the arrival of PCI, there appeared mainboards equipped with integrated PCI sound controllers, which, however, never really caught the spotlight due to their high cost. These sound controllers settled down in add-on sound cards. Still, the very idea of integrated sound was in the air. Soon, Intel took up this idea and suggested that the CPU could be made to process audio content. As the central processor involves only half of its potential power in most tasks, it could handle the additional workload well enough.
Thus, the only standalone element left was the switch unit for connection to speaker systems and external audio sources. Intel embodied this idea in a set of standards and specifications, and it was taken by the companies that manufactured chipsets and sound codecs. The serial digital interface between the controller and the switches was named AC-Link; it is a part of the AC'97 standard. Intel managed to unify the digital part, setting it apart from the analog one. Besides the connection to sound codecs, the AC-Link interface communicates with AMR and CNR ports (VIA calls the latter ACR). However, these connectors never grew popular and are now rare guests in modern mainboards.
Intel's specification for the South Bridge (Input/Output Controller Hub as the company calls it) lists AC-Link support as an obligatory feature of all company's chipsets. VIA and SiS followed the suit. However, there is always somebody who feels oppressed in the framework of standards and specifications. This time the innovator was NVIDIA that decided to change the South Bridge and implement the audio processing unit (APU) in some chipsets of the nForce2 family. We will talk about them later in this article.