User:Rtsai1111

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Hardware

I've been running a combined frontend/backend system since February 2005. It is pretty much dedicated to MythTV, although it does some other inconsequential stuff (rsync backup server, apache for mythweb). This system has replaced my TiVo (which I've given away to my brother); I've never looked back, and never missed it. The total monetary cost for MythTV has been $1555.60 + shipping (not shown). The system sits in the living room next to the TV, so I wanted quiet components. Much of the selection was heavily influenced by favorable reports on silentpcreview.com; I haven't been disappointed:

  • $50.99 - Antec SLK3000-B.
  • $79.99 - Seasonic Super Silencer 400.
  • $279.99 - AMD Athlon64 3500+.
  • $109 - Soltek SL-K8TPro-939. This was one of the few AGP motherboards with both optical input and output.
  • $49.95 - Thermalright XP-120 CPU heatsink.
  • $20.97 - 3 x Yate Loon 120mm fans (D12SL-12 x 3 - rear case exhaust, front intake, and CPU heatsink), undervolted to 5V.
  • $199.98 - 2 x Samsung SP1614C (160GB x 2).
  • $53 - Chaintech SH5200-128-DVI (nVidia FX5200). This one is fanless.
  • $357.39 - 2 x pcHDTV HD-3000.
  • $136 - Hauppauge PVR-500MCE.
  • $99.99 - 2 x 512MB Crucial PC3200 RAM.
  • $39.98 - 2 x Radio Shack 15-1868 VHF/UHF indoor antenna. I've tried the Zenith ZHDTV1 "Silver Sensor" and Radio Shack 15-1878 (indoor amplified antenna), but neither work as well. In a throwback to the days of rabbit-ear broadcast TV, I can receive all available channels broadcast in my area, but not with a single fixed antenna orientation. So each HD-3000 card gets an antenna to receive its own subset of channels (with some overlap between the two).
  • $29.97 - Radio Shack 15-2116 remote control.
  • $40.40 - Lite-On IR keyboard. This eliminates the need to fiddle with LIRC, and having a keyboard can be extremely handy.
  • $14 - JP1 cable.
  • Generic CD-RW drive cannibalized from an older system. It was used to install Ubuntu, and that's about all it's done.
  • Toshiba 42H83 rear-projection TV.
  • Toshiba SD-43HT cheapo home theater-in-a-box DVD player and audio receiver.

The system runs 24x7; it draws 80-122W (3.118kWH for an average day) depending on system activity (measured with a Kill-A-Watt). At $0.18/kWH (according to my last few electricity bills), this comes out to $0.56/day, or $15/month (!!). I may explore using Wake-on-LAN to shut down the system in between scheduled recordings; my problem is that the MythTV system is separated from the main wired network (holding the non-negotiably-always-on machine) by a sometimes tempermental wireless bridge. I don't want to miss a recording because the network happened to be out.

I had an extremely positive experience shopping at Mythic.TV. I e-mailed in a problem on a Sunday afternoon, and someone called me back on the phone within 30 minutes. I am not affiliated with Mythic.TV in any way beyond being a happy customer.

Software

  • Ubuntu 5.10 for amd64. I was a debian user for a long time before MythTV, but:
  • kernel-2.6.15.1. This was originally a 2.6.9 kernel with pcHDTV patches for the v4l drivers. It later got upgraded to a 2.6.12-rc kernel for the DVB drivers. New to 2.6.15 is "ATA passthru", which means that SMART information can be retrieved from SATA drives. Other kernel-related configuration:
    • JFS on LVM for 284GB of combined MythTV storage. The rest of the system lives on ext3. The drives run at 33-35C.
    • powernow-k8 w/cpufreq-ondemand. Most of the time the CPU runs at 1.0GHz (40C). It speeds up to 1.8GHz for watching live HDTV (55C), and only all the way up to 2.2GHz (just under 60C) for compiling software.
  • lm-sensors. The motherboard stays at around 35-40C.
  • hddtemp. Both hard drives run at 33-35C.
  • Xorg. The TV, despite claiming to support 1080i, is really just a 480p EDTV. It is configured to send a 960x540p modeline through the DVI output of the video card, but with overscan this ends up at 856x480. An Audio Authority 9A60 VGA-to-component adapter helped get the resolution up to 952x504, but that led to having to reset the TV convergence upon changing inputs. This hassle wasn't worth the extra little bit of resolution, so the 9A60 was removed from the system.
  • MythTV SVN. Interesting bits of MythTV configuration:
    • Content is auto-expired by priority (lowest priority first). This lets me keep my hard drive full without worrying about deleting content I care about. I just record all my "filler" content (Conan O'Brien, etc.) at some low priority so that it always gets auto-expired first.
    • Everything gets auto-mythtranscoded down to MPEG-4 at a variety of resolutions and uncompressed audio. Broadcast HDTV content consumes 7-8GB/hr; transcoding gets this down to about 1-2GB/hr. With my storage I have about 100+ hours of recorded television, plus MythGallery, MythMusic, and MythVideo content. I have "High Quality" set to 856x480@4400kbps, "Medium" set to 720x480@3300kbps, and "Low" set to 480x480@2200kbps. I don't notice that much of a degradation in quality from 856x480 to 720x480 to 480x480. As a bonus, the CPU can play back the transcoded content at a nice slow cool 1.0GHz. The mythtranscode configuration:
      • "Medium CPU usage" (e.g., nice +19), so it doesn't cause the CPU to increase its clock speed. At 1.0GHz, transcoding runs at about 0.5x real-time (2 hours to transcode a 1-hr recording).
      • Run transcoding before commflagging (backend setup); commflagging the transcoded content runs at about 6x real-time (10 minutes to commflag a 1-hr recording), much faster than commflagging pre-transcoded HD content.
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