8. Is PC-Based HDMI Ready For Prime Time? Continued

As long as HDMI outputs from a PC add SP/DIF based audio to the video coming out of whatever hi-def player is in use, sound recorded using any of the following formats can not be played back: Dolby TrueHD, Dolby Digital Plus or Dolby Digital Surround EX, nor any DTS-HD Master Audio or DTS High Resolution Audio, nor high bandwidth multi-channel Linear PCM. SP/DIF can't handle the formats required, limited as it is to AC3 data streams, which use 16-24 bit audio with a predisposition toward the low end of that spectrum.

This actually leads to our second conclusion from the recent sequences of media center PC builds for both the DIY HDMI article and this series - namely, if you want to build a fast, capable media PC, there's no compelling reason to buy HDMI gear just yet. However, you still might be inclined to do so if you think the convenience of a single cable from the PC to an A/V receiver outweighs the work involved in running a second audio line (optical or coaxial SP/DIF) or multiple analog inputs into that same receiver. HDMI gear is still new and somewhat expensive (premiums on motherboards and graphics cards for HDMI support range from 20% and up for this connection). Because you don't get the full benefit of the media's audio capability from the resulting set-ups, why spend the extra money?

If you really want to hear the high-end audio and view the best possible video, you may be better off buying standalone players because they include the audio codecs to handle 7.1 and 8 channel surround sound schemes, but also because they often include high-end signal processing circuitry from manufacturers such as Silicon Optix and Faroudja. This silicon can clean up video signals in hardware and may run better and faster than some software you would have to run to perform the same functions on PC-based player output. That said, upon initial analysis of ATI and Nvidia capabilities both seem pretty good. And with Blu-ray PC drives in the same price league as players and with HD-DVD PC drives all but unavailable anyway, except for the USB-based Xbox 360 and HP players, a standalone player looks like the best option for home entertainment centers today. This holds true for price/performance and the overall functionality each approach delivers.

Does this mean that HDMI in PC's is a total waste? Certainly not! The convenience of a single cable is hard to overstate, given the rat's nest typically found behind most A/V receivers. Another approach is already becoming available in the marketplace: AMD/ATI is shipping its 2900 series of graphics cards (which actually include 24xx, 26xx, and 29xx models), from which they can deliver integrated sound and image processing. They continue to use the same narrow-bandwidth AC3 method for passing audio data to HDMI that other graphics cards use. However, when bandwidth requirements for high-resolution formats such as Dolby Digital Plus, Dolby Digital Surround EX, Dolby TrueHD, DTS-HD Master Audio, and DTS High Resolution Audio can fit within this narrow bandwidth pipe - as AMD/ATI staffer, Dave Baumann, said they sometimes will - the new cards can transport high resolution audio through the HDMI link to an A/V receiver or TV set.