Home Theatre PC and all that…[1]

A few years ago I purchased a Mini-ITX chassis and installed a Gigabyte board with integrated CPU in it. This was supposed to get me something like a HTPC in a compact form factor that could fit in a small space next to a TV. However that board turned out to be too low powered to keep up with the demands of modern media playback requirements and is now unsuitable for its chosen role. Whilst I could replace the board, integrated boards are difficult to get and standard mini-ITX boards are quite expensive, difficult to fit into a small chassis like the one I have, or would overload the 90 watt power supply. It is difficult to save anything building your own computer in this form factor considering the low cost of the Intel NUC or various small form factor computers made by HP (like the Elitedesk 600 USFF I recently purchased to run Windows 10) when purchased second hand. It is possible a Raspberry Pi with a heatsink could make a reasonable media player which is something I still have to determine since the specs of the Pi keep increasing and they run Kodi quite well on a special stripped OS (libElec).

There are basically two types of mini-ITX board: those which use the conventional ATX type power supply, which have the 24 pin main power connector and the 8 pin CPU power connector, and those which have an input socket for a single DC voltage (a common one is 19 volts) and onboard componentry then produces the other voltages found in a typical pc. Both are readily available, the embedded CPU type of board tends to favour the latter option. My mistake was to spend money buying a chassis with a built in power supply (it connects a 19 volt 90 watt external adapter and then has a secondary board inside the chassis to produce the other voltages to standard onboard power connectors) that is just a little too small to supply non-embedded CPUs. For this reason I am not ruling out in future to have another go building a mini ITX system using the more expensive but well engineered Inwin Chopin chassis, which is very compact and incorporates a 150 watt small form factor (SFX/TFX?) power supply that connects directly to the mains. But for now I am not proceeding with this.

Hence I am replacing my Intel NUC with a more conventional system. The NUC has been great in the HTPC role until I discovered the VGA port would not work properly, meaning it cannot be connected to dual displays. Instead I have a small microATX Gigabyte H110M-S2H board which is basically a no frills system that I mistakenly bought a few years ago (it only has two memory socket and no M.2 socket). This can be fitted into either a low profile desktop chassis or something more specialised like the Silverstone Milo ML03 chassis which is designed with HTPC in mind. This can use a standard power supply but that makes it relatively large and is therefore unnecessary in situations where high power is not needed, for example if using the onboard graphics, a lower spec CPU, no cards etc. The Milo is like most of Silverstone’s current offering and in fact many chassis today which have the power supply mounted in the bottom of the chassis with the fan facing down, so that it moves air through its own grille in the base. Apart from the high likelihood of drawing dust, it means the chassis has to have feet with enough clearance to allow for this airflow, and internal power cables may not reach all the sockets on the motherboard. I’m not especially enamoured with the idea and still have a few spare conventional tower chassis around here such that this interesting but fairly odd design change won’t impact me. I did play with a Deepcool chassis of this design but apart from being very lightly constructed it had a few internal design issues I didn’t think much of.

In any case I went for a low profile desktop in the form of Inwin’s BL641 chassis, of which I recently picked up a pair on Trademe for the grand total of $112 including freight. They were without power supplies but otherwise in completely new condition. As a new one retails around $190, albeit with a power supply, as long as I could get a supply at a good price I was still doing quite well. As it happens I had four TFX power supplies in my cupboard stripped out of other chassis I had used in the past and putting one of those (a Seasonic) into one of the BL641s was pretty simple although they are only rated at 300W and in this case only had one of the P2 CPU power connectors i.e. 4 pin whereas the board has the socket for 8 pins. It is however possible to get away with only having 4 pins connected in lower power situations as long as the 12V2 rail can supply enough overall (hopefully the board also parallels its supply traces at the 8 pins of the socket). This board has a Pentium G CPU fitted, just like most of my systems, which is the lowest performing Pentium but better than a Celeron, the latter now almost having disappeared from view in the Pentium range. The BL641 chassis is formed into the horizontal “desktop” shape and takes a micro-ATX board with 5 drive bays (2 external), dimensions of 330 x 96 x 365 mm give it an internal volume of just 11.5 litres. The front panel carries 4 USB sockets (2x USB2 and 2x USB3) plus two audio. Here are some pictures of the design.

Inwin BL-641 chassis with a pair of feet supplied for vertical orientation. Next to the USB sockets are covered openings for additional optional peripherals such as Firewire or infrared interfaces. Front panel can have black or silver strip (latter shown).
Rear-above aspect of BL641. At the front of the computer is the detachable drive bay section which has on the left the 5.25″ optical external bay on top. A bay for a 2.5″ HDD is provided directly on the flat mount plate below this drive. Below this plate is the bay for a 3.5″ HDD mounted sideways. On the right side partially obscured are two 3.5″ drive bays, the upper of which is external-capable.
Above view of BL-641. The micro-ATX mainboard mounts into the large flat section where precut standouts are provided to match most common hole patterns. The TFX power supply snuggles up against a 80 mm fan which can be easily removed if the PSU needs changing.

The BL-641 is one of a series of similar Inwin SFF desktop chassis which only differ in the front panel design (the internal pictures shown above are identical throughout the range). It is comparable with the Foxconn DH153 chassis which is the only similar one I have encountered in OEM PC manufacture due to the ubiquity of proprietary chassised PCs from the likes of HP, Lenovo, Dell etc. However, the DH153 has to be larger at around 13 litres to compensate for its lack of innovation, namely a non-detachable drive bay, fewer drive bays, and a restricted 3.5″ external bay design that can only use a floppy drive (so no card reader, for example). DH153s I saw in use had only 40mm fans fitted which make a lot of noise when spun up to full speed on a hot day. The only real problem I can see with the BL-641 is lack of capability to attach it to a VESA mount bracket and I wouldn’t run out future rebuilding of this system if a VESA bracket capability or similar mount option became possible in future. As it stands, the chassis design makes it difficult to attach any sort of mount hardware to the base.

So I have my system built in one of these chassis now and am working with it already, the black chassis looks quite good and fits well into a smaller space, as well as having good performance etc.