14 August 2011

Mini ITX Gaming & Home Theatre PC

After having fallen in love with Mini ITX systems a few years ago, I have found myself making one my central media hub in my living room. Along side a gaming console and a good set of speakers, I could do everything I wanted when it came to sitting in front of the TV with my flat.

Recently having sold my xbox 360, I found myself having the itch for gaming again. My previous Mini ITX was and Intel Atom and Nvidia ION based system. Not the most powerful system but very low on power (Shown below).

Two and a half years from the build of that PC I decided to make a suitable gaming rig that had the compactness and elegance of my current mini ITX with the plan of reusing as many parts as possible. This idea however didn't last very long as I found myself having to replace all the parts due to incompatibility...

New System Specifications & Design

Processor: Intel core i3 3.06GHz
Ram: 4GB DDR3 dual channel 1333MHz
Graphics: Sapphire 1GB Radeon HD 6570
PSU: 150W mini PSU with 120W power brick
Motherboard: Zotac H55ITX-C-E
Case: 180x180x105mm DIY case

I couldn't find any commercial cases that where as small as I liked so decided to make my own. My previous design consisted of american white ash wood with 3mm aluminium plate on top and below. A large button with an array of blue LEDs next to it made the front stand out. This design was a lot of work and required a lot of wood working to get the sides smooth and give a good finish. It was also a problem when it came to mounting hardware, there was no rear I/O shield but rather a 18mm thick slot in the wood for the ports.

A new case was required to be tall enough for the graphics card and CPU cooler while still maintaining a slim look. I decided to use 9mm MDF on the sides, top and bottom, while using 3mm aluminium panels on the front and back.

Having moved into a new student house I couldn't bring a table saw or larger power tools with me from home so I outsourced as much as possible.

The case was designed from taking measurements from the assembled PC components and modelled in Autodesk Inventor.


http://www.iplaser.com/ was used for the aluminium panels. This cost around £48 and arrived in 2 and a half weeks.
http://www.craftyboardz.co.uk/ was used for the MDF panels. This cost around £15 for 1220x1220x9mm MDF cut into required pieces and arrived in 3 days.

It was great having the MDF precut and laser cut panels for so cheap, compared to buying a case. I planned to finish the sides with black speaker cloth and top and bottom panels with a red textured wallpaper sealed with clear coat spray varnish.

These are the case parts designed in Autodesk Inventor according to the Mini ITX spec and by taking various measurements of the assembled PC components.

The first thing to do was sand the all the panels. The metal ones where scrubbed down with a wet 120 grit sand paper and the MDF cleaned up with a medium grain general purpose paper.

Next the fan holes where cut into the side MDF panels and edges given some radius for smooth air flow.

Holes where cut with a 38mm hole saw and then four 40mm blue LED Akasa fans screwed on. I put all the fans in a parallel connection with a total power draw of 3.2W. The panels where covered in aluminium tape on the inside to serve as shielding.

The power button was to be side mounted under the speaker cloth and serve as a "hidden button" in order keep the front face clean of fixtures (I originally wanted a logo cut out on the front face but the design was too fine to laser cut so removed it). The switch is actually very easy to find as it sticks out enough to feel it without seeing it..

The top and bottom where finished using spray glue to stick on the wallpaper before being pulled tight around the edges of the board and being held down with more aluminium tape.

The enamel clear coat was used to spray a gloss finish on the panels.

Next came the fitting of parts...

Aligning the HDD mount (I believe it's an acer laptop hdd bracket, I found on ebay very cheap). Note that there is space for another mount.

Screwing on the mount...

Mounting the drive...

Not a very big drive, I plan to replace it soon with an small SSD and a second terabyte disk drive at some point when student funds allow.

Here mounting the motherboard stand offs.

First driven in with a driver, then hand tightened in order to not damage the MDF...

Again dimensions taken form Mini ITX spec sheet, above shows the motherboard being screwed on.

Now plugging in the components!

RAM and Mini PSU shown above. The PSU uses a standard DC power jack for 12V input and then regulates all the other system voltages. Should be good up to 150W.

Here the IO shield is clipped in...

The panels where then screwed on using chrome Hex screws (found at speaker stores)...

Using some clamps here to hold things still while using a sharpie to make a dot and drill...

Pre drilled 2.5mm holes for screws prevents MDF splitting...

Screwing on the panels with an Allen key. Again careful not to over tighten and damage the MDF...

Dropping in the graphics card...

The graphics card is a low profile card, it comes with 2 types of brackets that accommodate for shallow cases. I had to do some modifications to the bracket as I didn't design the actual port holes into the metal rear panel, but rather a slot.

The two shorter mounts allow the VGA port to be moved from above the HDMI to next to it. The VGA port  is removable and as I wouldn't need it, it's therefore not included in the build.

Here I flattened out the tab and cut a notch that stuck out and held to the rear panel as shown below.

A sturdy fit!

Time to hook up the HDD...

Don't forget this power connector!

This is a 4pin to 3pin fan converter, it uses a MOSFET driven by the PWM pin to switch the fan power line. It's built on a simple strip board and uses a diode, two resistors and a MOSFET.

Soldered on the power switch connector...

The side panels being covered in speaker cloth...

Using a staple gun the cloth stretches around nicely and does a great job of filling in any gaps in the MDF alignment.

Here is the finished product with the sides covered and screwed in place. Enjoy!

The accessories used with this systems shown below consist of a 120W power brick, two wifi antennas, two wireless 360 controllers, a 360 controller USB receiver and a Lenovo remote keyboard with trackball.

The system is currently hooked up to a 22" Viewsonic monitor via HDMI running at 1080p. The sound goes out to a 5.1 system that is currently being finished (look forward to this upcoming project soon to be posted).

The PC also acts as a central hub for sound as the audio from my Virgin media cable box also connects to it. Due to the fact that the PC is always on, the sound is always available.


Using Windows 7 pro 64bit, core temp to monitor temperature and Prime95 x64 to stress test.

Default settings:
   CPU speed: 3066MHz
   CPU voltage: Default
   CPU min temp: 44degC
   CPU max temp: 100+degC (Way too hot)
   Mains power drawn idle: 52W
   Mains power drawn full load: 130W

Modified settings:
   CPU speed: 3580MHz
   CPU voltage: -0.1V (Lowest it will go)
   CPU min temp: 44degC
   CPU max temp: ~90degC (Rises much slower)
   Mains power drawn idle: 52W
   Mains power drawn full load: 112W

Conclusion and improvements

The few problems that I came across were all simple fixes. Originally I only had a 60W power brick at hand and this resulted in a very unstable system. After a short time after having installed windows for the first time, the system would often refuse to boot. I used a friends 600W PC supply to test my system and measured 7 - 8 amps of current drawn during boot up. A new power brick was obtained and problem solved.

During the build you may have noticed one of the four Akasa fans conflicting with the ram stick slots. This was fixed by moving the fan up a little and re screwing it down.

A final detail was a small misalignment in the MDF panels once they were screwed on. This caused a gap on one side, and the part to stick out about 1mm on the other side. It was however covered up by the speaker cloth and is no longer noticeable. 

I also believe that the power button has been a bit damaged while being pressed into the side panel and now requires a bit more pressure to activate, if this becomes worse, I shall replace the button.

Apart from that the system runs well, I need to find a way of controlling the case fan speed in windows as they run at full speed while idle and are very audible in a quiet room.

I have over clocked the system to beyond 3.8GHz with standard voltages. This is more than required so I decided to drop the voltage down as much as possible while staying above 3.5GHz. It turns out that I can go to the lowest CPU voltage whilst maintaining a stable system just under 3.58GHz.

Tested stable with Prime95, however will BSOD during a windows performance check...

The system in general use however is very stable so for now, these settings shall suffice.

Currently Dirt3 runs well on high settings, PCSX2 runs Gran Tourismo 2 around 50-60fps.

That's all for now, thanks for looking, please comment!

More projects soon =].


Update: 17/08/2011

Came across a problem with the case fans. It turns out that the 4-pin system fan connector on the Zotac H55ITX doesn't actually have speed control. That of course meant that the case fans sat at full speed being noisy...

A way round this was to connect the CPU fan in parallel with the case fan. That way they are controlled together in accordance with CPU load. I soldered three wires for 12V, GND & PWM coming out of the CPU fan connector and going to the case fan.

The wallpaper finish seems to be peeling off the MDF, probably due to the heat. ARGH!!!

I don't think I'll use that finish again, unless I can figure out a better way of sticking it down. Some iron on veneer glue stuff? Anyone know of anything good?

Could have gotten a better look painting it perhaps...

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