New to this All-In-Wonder is streaming audio, where audio is compressed to data and streamed simultaneously with video through the PCI bus. This aids people too unskilled to connect an audio cable to the soundcard, but is primarily intended to address problems of audio/video time synchronicity.
ATI's implementation of streaming sound requires a buffer, even when TV-on-Demand (the buffer used to replay live TV) is disabled. When you change a channel, video takes one second to change, audio an additional second. One to three seconds later the sound might skip briefly (for less than a second). Other adjustments to the TV program can also cause this brief skip.
Because we never had any of the problems ATI solved with streaming audio, we'd appreciate the return of soundcard inputs (buffer off) as a driver option accessible in TV-Setup. The All-In-Wonder X800 XT still provides internal 4-pin and external mini-jack soundcard connectors, but they're no longer used by the driver. We're all familiar with options lists that provide recommended and alternative settings, and the hardware is there for both.
ATI Professional Services claims that channel change delays were addressed in MMC 9.06.1, but that some delay persists due to buffering. Indeed, testing showed delay reduced, but not eliminated, using ATI's latest Catalyst 5.4 drivers and MMC 9.06.1 software. We find it disheartening that turning off TV-on-Demand no longer provides live TV, and especially annoying when a nearby television is set to the same channel. The future of ATI is compulsory time shifting, due to buffering, with no options to disable it.
Further testing showed a complete workaround for those who'd rather use a stereo cable and eliminate lag/buffering entirely. Installing Catalyst 4.11 and updating only the tuner driver - the one feature not supported in version 4.11 - eliminated streaming audio and related buffering, while re-enabling soundcard input selection from Multimedia Center's TV-Initialization Wizard. Alternatively, installing later drivers and rolling back the "TV Audio Crossbar" driver provides cabled sound without buffering, but doesn't allow you to select your audio source for MMC volume controls. It should go without saying that using a non-approved driver configuration puts any stability problems that may occur in the hands of the user, though we didn't experience any.
Tuner lag has now been fully investigated. Using a cable connection from the tuner to the soundcard (no buffer), rather than streaming audio (with forced buffer), restored the lightning quick channel changes and truly live TV of previous cards. Far be it from us to blame the new tuner without fully investigating the actual cause!