Assuming we are building a HTPC mainly for playing A/V media, not playing games, the most important thing but often overlooked or not emphasized by most the review on motherboard or graphics card is the ability to support HD audio such as DTS-HD MA or DD TrueHD bit stream.
Am I saying audio is a more important factor than video in HTPC? No. Not really. But consider today’s new generation of graphics chips from ATI, Intel or Nvidia all supports HD video playback that off loads from the CPU. Even new IGP on motherboard chip sets such as ATI 4200, Intel X4500 or GeForce 9300, they all able to play the HD DVD or Blu-Ray smoothly without the need of high power CPU. In fact, even older CPUs such as AMD Athlon 64×2 5200+ or Intel Core 2 Duo E4300 can play Blu-Ray nicely with those IGPs.
The HD audio that is part of the Blu-Ray experiences on the other hand is very different story. One can not assume just because the motherboard or the graphics card has a HDMI port on it and the manufactures mentions audio pass through, they will support DTS-HD MA and DD TrueHD. In fact, none of the current IGP chipset supports in.
The AMD’s ATI 4200 from the current 785 and 890 chipset is the worst as it only supports 2 channel PCM audio through HDMI. By itself it would not even support the pass through of basic 5.1 DTS or DD core! It require additional s/w and/or h/w support to do so.The new AMD 890 chipset is particular disappointing as AMD clearly do not want it is used as HTPC motherboard without the need of adding additional graphics card.
The Intel X4500 or the GeForce 9xxx (including the 9400 used by the Ion platform) is only marginally better than the ATI 4200 on audio. While they do support 8 channels LPCM output, they don’t support DTS-HD MA and DD TrueHD. Again, external h/w or s/w decoding is needed to decode the HD audio bit streams to LPCM. If s/w solution is used, it will place a heavy burden to the CPU which requires more powerful and more expensive CPU and possibly memory too. In addition, although some people argue that LPCM conversion done right will preserve the lossless nature of the DTS-HD MA or DD TrueHD, but that will be putting a lot of faith to who ever is implementing the decoding in h/w or s/w to do the right thing not to cut corners to cut cost or gain performance or both. I for one rather want to see the original bit streams pass though the HDMI port to the receiver.
If none of those motherboards with built-in IGP can support native HD audio bit stream, then none of them, at least not by themselves is suitable for HTPC application. Built-in IGP or HDMI on the motherboard is therefore not a factor or even desirable when choosing a motherboard because of possible higher cost and power consumption for the parts that are useless.
While some of the new Intel i series CPU had built-in GPU that do support DTS-HD MA or DD TrueHD, The CPU plus motherboard combo is far more expensive than necessary. A better or less cost solution is to use older or lowly motherboard and CPU combo that using older DDR2 memory can be had around $50 is adequate.
When it comes to add-on graphics card, the real sections are between ATI and Nvidia. I was very surprised to find out none of their new generation of graphics cards from GeForce 240 on down supports native DTS-HD MA and DD TrueHD. They all require conversion to LPCM. As stated before, I don’t consider this conversion is acceptable for today’s HTPC at all. I did not bother to look Nvidia’s line above the GeForce 240 as their costs are way beyond what I have in mind for good budget HTPC.
On the ATI side, I did not look at their older 3xxx or 4xxxx series as the ATI 4200 did not give me a good impression. The ATI 5450 is the current entry model for the 5xxxx series and it is prefect for budget HTPC. First and foremost, it supports DTS-HD MA and DD True-HD pass through. Second, it and no fan and therefore no fan noise. Third it cost less than $50. While ATI 5450’s game playing ability is questionable, it plays all HD video files smoothly and with minimum demand to the CPU.
The advantage of using low power graphics card, CPU and motherboard means there is no need for high wattage power supply too. I used a 500W power supply not because I need one but rather it was no sale for $20. Some people may say these cheap power supplies’s real wattage does not even come close to the advertised number. But even if this power supply’s true wattage is only half of the 500W advertised, it is still more than enough to power my HTPC. The entire setup with ATI 5450, AMD Althon II x3 440, MSI 785GTM-E45 motherboard, two 1.5TB hard drivers, two optical drivers and uses less than 140W when playing Blu-Ray movies. My older CPU and motherboard combo uses even less power.
Speaking of AMD Althon II X3 440 and the MSI motherboard combo, I got them on sale and at the time I thought the MSI motherboard hat uses AMD 785 chipset will support DTS-HD MA etc. If I knew what I know now, I would have just added the ATI 5450 to an old PC setup that has AMD Althon 64X2 5200+ CPU as it can play the HD media just as smooth as the real work is done by the ATI 5450.
For HDTV tuner, I used a USB external tuner from Kworld. While I can never get the QAM tuner to work, it is not a great lost as the Windows 7’s MCE doesn’t support QAM and the local cable’s QAM offering is worst than ASTC any way.
The total cost of building this HTPC is very low as most of the components came from existing PC. As I have mentioned before, if I had know better, all I really needed to change the existing PC to HTPC is the ATI 5450 card that cost $40. Even in case I need to start from ground up, the cost would be about the same as a TVIX 6620N or Dune Prime but capable to do more than either of them can provided.
For people who do want to assemble a HTPC from ground up, they can get a decent desktop PC for around $300 from many retail places as long as the PC has empty PCIe slot to put in a ATI 5450 and that’s it.
As for media player software, the Media Center that came with Windows Vista and Windows 7 although not great but is more than functional. If you buy a retail version of the Blu-Ray drive, it is also likely to be bundled with player software that can play both Blu-Ray and DVD.
Bottom line, there is no need to get latest greatest CPU or GPU to build a great HTPC. Video play back for HD content is widely supported even by entry level GPU or motherboard IGP that came to market in the last year or so. HD audio support on the other hand is different story. Most of if not all of the current motherboard IGP and low end to mid range Nividia solution is not capable of full HD audio support. Some thing to watch out when building a HTPC.