MicroATX boards for a MythTV HTPC

When the power failed Wednesday, the house was quiet because I had to power down all my electronica. Individually, each piece is quiet, but added together, there’s a definite background noise. As I powered up each computer individually, it was easy to see what contribution it made to the overall noise level.

It turns out that my MythTV system is louder than I thought. The main problem is the 60 mm case fans, even though I have them undervolted. As part of a home-theater redesign, I’ve been thinking of re-spinning the hardware on the MythTV system to make it smaller, so I might as well try to quiet it further as well.

I’ve learned a couple of lessons on the case. Lesson One is that a full-size ATX case is big. The Silverstone is nice-looking, but it’s still big. It’s too deep for most home theater furniture, and it’s easily the biggest piece of equipment that I need to work with. Lesson Two is that the acoustics of the case aren’t that great, and that 60 mm fans should be banished from any HTPC case. (I purchased the case in early 2005, and 60 mm fans were hard to avoid then.)

I’ve been impressed with the reviews of the Antec NSK 2400 case, which isn’t surprising. Mike Chin of Silent PC Review was a consultant on the design. He recently worked with EndPCNoise.com to design off-the-shelf systems, and the SPCR-designed HTPC uses the NSK. I will probably go with the Antec Fusion, which has a VFD and covered drive bay, but is otherwise the same case.

The downside of using the NSK is that I’ll need to totally re-spin the hardware, since the NSK is designed for MicroATX motherboards. To pick out a new motherboard, I started with a wishlist:

  • Video chipset. mATX motherboards usually have limited slots, so I would like built-in graphics. I’ll be running MythTV, so nVidia is preferable because their drivers are more Linux-friendly than ATI. However, the chipset isn’t everything, because I have concerns about the…
  • video connector. I do not want to take up a slot to get the right output form factor. Ideally, the board would have a standard-definition output (either composite or S-Video), and forward-compatible HD output. HDTVs all seem to want HDMI, but it is possible to buy a HDMI-to-DVI cable, since the electrical signaling is the same between the two. If HDMI or DVI is unavailable, then component outputs are acceptable.
  • Optical audio output (S/PDIF), to transport the 5.1 digital sound broadcast with HD 5.1 to my receiver. One cable is easier than six, and I already have the digital audio cable run in my current cabinet. In a pinch, I might be willing to settle for six analog outputs and a cable control solution, but that would be ugly.
  • Southbridge. I’m not real picky on this chip, but there is one feature I’d like. It’s apparently possible to watch sports without listening to inane announcers by muting the center channel audio in a 5.1 broadcast. My receiver has the tools for doing this, but there may be some support required in the audio chipset.

I am staying agnostic on the CPU. In the past, AMD motherboards have been much cheaper, especially when you pair them with a low-power CPU. Intel has generally discouraged use of the ultra-low power Pentium M in a non-laptop setting, and the high prices of Pentium M-compatible motherboards reflect that. If I were to stay AMD, I would prefer to stay with the old socket 939 form factor because I could re-use my existing CPU, but that’s not really important.

My usual procedure is to head over to newegg.com and fire up their search engine to sort through the huge universe of motherboards. (They don’t carry AOpen motherboards any more, though.) In the Intel world, there is only one Socket479 mATX motherboard, the Asus N4L-VM DH, which doesn’t have DVI output.

As I expected, the AMD world has more choices, but all of them have a minor annoyance:

  • Asus M2NPV-VM. This is the motherboard used in the EndPCNoise Model Eleven designed in conjunction with SilentPCReview. The annoyance is that the on-board audio controller doesn’t have digital outputs. To add digital outputs, I would need to buy an add on PCI Express card because both PCI slots will be occupied by tuners. (Come on, Asus! Does this board really need a parallel port? Take that off and replace it with a S/PDIF optical port.)
  • Abit NF-M2. Abit has had some quality problems in the past, which is a small downside to this board. It’s almost completely “legacy-free.” Not only are there no parallel or serial ports, but the board doesn’t even have headers for them. I would need to buy a new remote control sensor to work with USB, instead of using my existing serial port remote sensor. My main problem with this board is one of backwards-compatibility, though. Right now, I am still using a standard definition TV, and the video solution on this board lacks a standard-definition output. Interestingly, this board has two S/PDIF ports, though I can’t see using the input port any time in the near future.
  • DFI Infinity C51PV-M2/G. This board has everything on my list, with the possible exception of the hard-to-verify audio switchability. However, it’s not really a mATX board. The maximum size of a mATX board is specified as 244 mm x 244 mm (roughly 9.6 inches square), and this board measures out at 244 x 264 mm. On one side, it’s 2 cm too long (or almost an inch). I am not sure if this would be a problem in the Antec case, and I’m not going to order it and find out.

One other notable mention is the DFI RS482 Infinity. Unlike the previously mentioned DFI board, it is 244 mm x 244 mm, and would fit in a mATX case without difficulty. SilentPCReview has praised its undervoltability and power saving capabilities. However, it is based on an ATI graphics chipset, which seems like a pretty big risk to take with MythTV.

4 Responses to “MicroATX boards for a MythTV HTPC”

  1. P Kuronen says:

    DFI RS482 Infinity’s ATI graphics chipset is a risk with MythTV?

    I have a MythTV box connected to projector with DVI-D – HDMI cable. At first I used nVidia Geforce display adapter and had to do a lot of work to get picture and output settings correct. When the nVidia card got broken I decided to try out my ATI Radeon (8500 maybe.. dont remember anymore) since it had DVI-D and surprise! It went just like that, Xorg autodetected the display modes from my projector and I did zero work to get it going. The standard Fedora radeon driver worked like a charm and the picture quality is far better than the terrible flaky pictures of factory set-top digiboxes I’ve encountered so far. So based on this I definately recommend ATI Radeon based display cards for HTPC usage, just don’t go for the latest models. They are of no use in HTPC since even my old Radeon handles MythTV’s OpenGL effects nicely.

  2. matthew says:

    I selected the DFI RS482 Infinity for my Asterisk system, because I wanted to use an AMD Turion CPU, and it was the only board that supported Cool’n’Quiet with the Turion. I’ve had a lot of problems getting the ATI chipset to work well under Gentoo, so maybe it’s just that the Radeon support is better worked out with the Fedora distribution.

  3. Lee says:

    Avoid the DFI RS482 Infinity if you want SPDIF sound. As it is now you’ll have to manually patch your kernel to get the analog sound working. I can’t seem to get SPIDF working no matter what I do though. I think I am going to switch to that ABIT board soon.

  4. Marko says:

    Asus M2NPV-VM does have digital audio out. There’s just a header for that. The suitable backplate needs to be purchaced separately. This backplate has coaxial and optical audio out.

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