Asustek Computer, a leading maker of mainboards, graphics cards and other computer components, recently unveiled its new Xonar DX PCI Express 7.1 discrete audio card claiming that its new device supports Creative Technology’s Environmental Audio Extensions (EAX) 5.0 and allow gamers to enjoy higher quality audio in games. But Creative Technology claims that Asus’ audio card does not support EAX 5.0 at all.

“With the new audio architecture in Vista, users will sometimes be unable to achieve multi-channel sounds, DirectSound; and EAX 5.0 sound effects in EAX 5.0 Titled PC games. With the ASUS Xonar DX, all these problems will be solved,” Asustek Computer said in a statement early in March.

In fact, the situation with EAX as well as hardware-accelerated audio support under Microsoft Windows Vista is rather complicated. The operating system does not allow using hardware-accelerated audio with the help of DirectSound/Direct3D, however, hardware acceleration of audio processing may be exposed either through OpenAL application programming interface or through Creative Technology’s ALChemy driver.

“With support for the innovative DS3D GX 2.0 technology, the Xonar DX automatically supports the latest EAX and DirectSound HW after installation without the need to search for additional drivers or OpenAL – as most games are DS3D/DirectX compatible,” Asustek said, promising support of EAX 3.0, 4.0 and 5.0 features with its Asus Xonar DX PCI Express 7.1 discrete audio card.

Theoretically, it is possible to emulate EAX 3.0, 4.0 and 5.0 capabilities using driver and “report” a software that certain feature is supported in hardware, whereas in reality it is not. According to Creative Technology, emulation is exactly what Asus software does.

“With its recent driver updates, Asus is misleading its customers by suggesting that its sound cards now support EAX 5. Asus sound cards do not support EAX 5, nor do they support EAX 3 or EAX 4. There are a small number of PC game titles that specifically query the audio device on the system to see if EAX 5 is available before they will attempt to render more than 64 3D simultaneous audio voices. The new Asus drivers are falsely reporting EAX 5 capabilities in order to get these games to ouptut 3D audio on Asus sound cards,” said Phil O’Shaughnessy, vice president of corporate communications at Creative Labs.

Even though it is possible to emulate presence of EAX 3.0, 4.0 and 5.0 hardware through software, the actual audio processing will be performed by the microprocessor, which may not be capable of processing up to 128 voices with up to 4 effects applied to each without issues. As a consequence, either the audio quality or game performance may degrade dramatically.

“Asus customers are not getting a genuine EAX Advanced HD experience with this driver update. Furthermore, the several hundred games that support EAX 3 or EAX 4 for delivering in-game effects will not provide those effects from Asus sound cards,” Mr. O’Shaughnessy added.