Leo Maxwell decides to increase his resolution for the New Year
Many of us are interested in the versatility of a media PC (sometimes called a home theatre PC, or HTPC for short), but is it worth building your own? If you only want a comparatively simple PVR, there are many hardware based solutions, some more accomplished than others. If you just want to watch the odd TV program on your PC, then you just need a simple media player. What we are talking about, though, is a dedicated PC to supply all of your home entertainment requirements.
A media PC can function as a TV, PVR, Blu-ray player, jukebox, streaming server and offer many other functions in one box, which can all be operated from a single remote control. Commercially available HTPC generally command a premium price, for various reasons. They are designed to give adequate video performance without requiring noisy cooling fans, and they usually have a non-standard case, sometimes with an external power supply. Some have custom cooling arrangements such as large heatsinks (sometimes the case itself functions as a heatsink) and large, slow fans or no fans at all. They may use rubber disk mounts to reduce vibration and noise, and so on.
They often use laptop style hard disks and optical drives. These are smaller, quieter, and less power hungry than the full size items, but this also means that they are more expensive. The software is often Windows with Media Center or other proprietary software although some are Linux based.
The higher price of the top-end hardware and the lack of sophistication of the lower-end models may prompt you to build your own, and that is what we will be looking at in this article.
The DIY Option
Initially, the plan was to to upgrade my existing MSI Media Live! unit, which has been providing excellent service for the last five years. Purchased in 2008, this PC has sat in my living room and ran MythTV on Linux. It was intended to be a multi-functional unit for a variety of tasks, but it ended up mainly being used for watching and recording TV.
When I started looking around at options, however, I was quite surprised by the advances in low-power computing since my original build. The previous media PC case was quite large and had various options that I no longer required – including wi-fi, a fluorescent display, an optical drive and a card reader. So, I decided to try something more compact (and hopefully more energy efficient too).
When deciding on hardware for a machine that’s intended to be switched on 24/7, there are several things to consider. Noise can be an important issue, especially if the device is in the living room under the TV.
The main sources of noise are fans, hard disks and optical drives. Large fans that can spin more slowly, sound insulation and rubber mountings can help a lot, as can passive cooling and careful choice of components. For this sort of application you would previously have needed what was considered a fairly powerful CPU, but these days a lot of video processing and decoding can be offloaded onto the GPU so that’s not so much the case anymore.
With this in mind, I chose one of the recent AMD Kabini series of socketed processors, in the form of a quad-core 2.05GHz APU coupled to a mini-ITX motherboard and 4GB of low-latency memory. Although I could have used a much less powerful processor, I wanted this device to be multi-functional, as I would be making use of this as a replacement for another PC as well, which resides in our Kitchen.
Some long term Micro Mart readers may remember an article in the January 2009 issue about building a Kitchen PC. This unit has since resided under my kitchen work surface, mainly used as a digital picture frame, recipe database and music player. The Internet is also an excellent resource for researching recipes, cooking techniques and other information. The on-board Intel graphics did not really work very well with newer Linux distros, however, so I had decided to incorporate my back-end TV and media server into it.
This PC could sit under your TV, or it could be located anywhere in your house with access to a power supply, TV aerial and a network connection to make media available to PCs, Phones, Tablets and many other devices. The media streamer in my living room, for example, is a MINIX AndroidTV unit with XBMC as the front-end player.
The TV Card
SD DBTV Freeview cards, which can receive all of the unencrypted terrestrial free to air channels, and have two or more tuners, are available quite readily and cheaply, in USB, PCI and PCIe formats. The range of available HD DVB2-TV cards is comparatively small at the moment, possibly because of the shrinkage in the traditional PC market. Not all of those that exist support Linux, either, which was a requirement of mine. It is important to read the specifications carefully as, like many ‘HDready’ TVs, some ‘HD’ TV cards cannot actually receive HDTV signals. Before purchasing, make sure that your chosen unit will fit your PC, and that it supports your chosen Operating system.
It is also important to decide on the number of tuners you require, as a single tuner means that you can watch or record TV, but not both at the same time.
The best known manufacturers of HDTV PCI-E Tuners are TBS, BlackGold and Hauppuage. PCTV Systems also offer the 292e NanoStick HDTV USB tuner, which is a single tuner unit. I decided on a TBS6281 dual tuner card, though, as it supports Linux and has good feedback from the Linux community.
TBS also makes Freesat cards and quad-tuner units. I live in an area with a good Freeview signal, and the software I was intending to use can record multiple channels from a single tuner, so I was happy to go with a dual tuner terrestrial unit. In the years that I have used my previous SD Dual tuner card, I have rarely been unable to record any program I want.
Most cards come with an infra-red receiver and a remote control. The cheaper ones are not terribly good, but the TBS one seems okay. Most PCTV remotes will work with the card, as the OS is used to control the media. Windows Media Center remotes are usually quite good, and easy to find online.
TV cards vary in sensitivity, so a good aerial is recommended, especially for HD transmissions.
As an hour of SDTV takes around 2-3GB, and an hour of HDTV can fill up to 8GB, a large hard disk is a necessity. I fitted a 1TB hard disk, which is fine for me, as I rarely store recordings for long. You may want a bigger drive, or even multiple disks. It is surprising how quickly the drive can fill up, especially if you record a series for binge viewing later on.
Energy usage is an important concern, as the device may need to be switched on 24/7, although sleep mode can be used to save power when the PC is not in use. TV server software can be set to switch the PC on to record a program, returning to sleep when the recording is completed. Media front-ends, such as XBMC can be configured to send a wake up signal over the network to a dormant back-end server when wanting to access LiveTV or media files. This is known as “wake on lan” or “WOL”.
If you want to suspend the PC between recordings, you will also need to set up the RTC (Real Time Clock) wakeup. Both of these settings need to be enabled in the machine’s BIOS, and the method will vary depending on the Motherboard and software in use.
Building The Box
While it is not currently possible to build a PC quite as small as most dedicated PVRs you’ll come across, you can get somewhere near to that sort of form factor. Indeed, some cases are now small enough to mount on the rear of a monitor or TV. My choice of case was limited by two factors, though: firstly, I wanted a dual tuner HDTV card (which meant a PCI-E slot), and it had to fit the small space I had available for it, which meant it could be no wider than 100mm.
I had initially intended to use an existing case with a PCI-E riser, in order to fit the tuner card in a horizontal backplane slot. This plan was eventually scuppered however as, in reality, when I fitted the TV card it lay across the top of the CPU fan. This meant that I needed a case with a vertical slot for a half-height card. The In-Win case I finally decided upon was quite roomy, with space for a full size optical disk and two hard drives. The L shaped cover is held in place by two plastic clips, making for easy access. It came with a pre-fitted 200W power supply and a case fan.
The fan on the stock Kabini cooler was surprisingly loud, though. In the default mode, it was louder than either the case or power supply fans, resonating in the case to an annoying amount, and to the extent that I began to regret not choosing a lower power fanless design. Happily, altering the fan speed settings in the BIOS reduced the sound to an acceptable level without affecting the processor temperature unduly. I could find no AM1 replacement coolers currently on sale in the UK, but Gelid and Noctua have both announced impending models.
The fan in supplied 200W PSU was not loud but I decided to reduce the heat in the enclosure by fitting a PicoPSU, in the hope that I could also dispense with the case fan. Although I have run this setup without issue on an 80W miniPSU, but ultimately I decided to go for a 160W unit with reserves for possible future expansion should I end up encountering as yet unforseen applications.
A PicoPSU is basically a small circuit board mounted on a 24-pin plug, which plugs directly into the motherboard. It receives 12V DC from an external power brick, which does the heavy work of reducing 240V AC to 12V DC, and shedding most of the heat involved in that process out into the surrounding environment. The PicoPSU has voltage regulators to produce 12V, 5V and 3.3V DC, and fly leads to connect the additional four-in plug for the motherboard and so that it can supply power to the drives.
The completed unit is quiet and performs the tasks I’ve asked of it well, certainly far better than the unit it replaced. I suppose that it is really over-specified for its intended role. Though at least that means it will serve me well for some time to come.
Both Linux and Windows installation were responsive and pleasant in use, and it coped easily with the demands of the media software I installed. So, at the very least, the project can be considered a success – and not all that stressful.
Gaming would probably not be a good idea with a system like this. Having said that, it might well cope with some low level stuff or browser-based games that seem very popular… Certainly enough to pass the time while cooking.