Monday, 30 April 2012

HTPC Build successful, though not without bumps along the road!

After much fiddling, I've finally got my HTPC up and running.  My initial assembly went smoothly enough, however, the system wouldn't boot.  After some trial and error searching for the cause, it turned out the Pareema RAM was the culprit: Stealing a 4gb Mushkin module from my desktop lead to a successful boot up.  Curiously, neither of the Pareema modules would work - normally, it's just one of a pair that's bunk - I need to try these in my desktop, just to be sure it's not an oddball compatibility issue.

Anyhow, moving on.

While assembling the PC, I noted that the power supply in the case is mounted above the motherboard's CPU slot, and that it's air intake is right opposite the CPU cooler's fan.  While the A6-3500's cooler would physically fit under the power supply, half it's fan would be blocked with only about a 1/4" clearance - and as the PSU's intake fan was right there, the two fans would be starved for air.  Add the PSU's absurdly long cables crammed in between the optical drive and the PSU, there was precious little open space for air flow to the rest of the CPU fan.

Anticipating heat being a concern in such a tiny box, I'd picked up a 120mm 920rpm fan as a case fan: The large diameter and low RPM allow a substantial amount of air movement (optimally 45CFM) to push more air through.  Mounted in the second hard drive bay on the side of the chassis, it moved a fair amount of air through the case, but alas, heat was still an issue.

Once running, the CPU would steadily climb up to around 45 degrees C at idle, with the CPU cooler fan pushing up to maximum speed (which, incidentally, sounds remarkably like a jet engine).  Under load, the system would overheat and shut down.  I tried dropping the clock speed down to 1800mhz (the A6-3500 runs at 2100mhz stock, with a "turbo" speed of 2400mhz for one core) and the voltage down to 1.3v from 1.4.  Unfortunately, while it did run a bit cooler, still not sufficiently.

Obviously, this was untenable.  Having your HTPC shut down in mid-movie isn't exactly the behaviour you want from your HTPC, unless you're watching something spectacularly terrible, and having to turn up your TV to hear it over the miniature jet engine wailing beside it detracts from the experience.

So, I pulled out the power supply.  The ridiculously long cables then became an advantage, instead of a disadvantage: I could run the power supply entirely out of the case without any trouble at all.  Now, I'm not considering staying this way, but I wanted to be sure that with the power supply out of the picture, the system would work out well.

And, fortunately, it does.  With the power supply out, the CPU fan at 40% speed (whisper quiet), the system runs at 36c under load.  Experimenting, I was able to overclock the system clock to 2500mhz (on all three cores, just disabling the silly "Turbo" thing), the GPU portion of the processor from 450mhz to 550mhz, and the RAM from 1333mhz to 1600mhz, with core temperatures not exceeding 39c under load.

So, moving forward, I'm replacing the power supply with a 120w picoPSU from Short Circuit, basically just a plug in your box and a laptop power brick.  120w is much more than is needed, with the full system drawing at most 85w under stress testing (~60w during playback) but the next one down, 90w, is uncomfortably close to the peak power draw from the system.

Wednesday, 18 April 2012

Damn it, I'll do it myself. My first HTPC build!

The Problem:

With the birth of our new baby and a move from Vancouver BC, to Calgary, Alberta has shown me that my current home entertainment setup is entirely too unwieldly and begging for something terrible from the little munchkin.  Half a dozen various game consoles, set top boxes, media players, all strung together with too-long cables twisting into a labyrinthine tangle Cthulhu would be intimidated by.  Furthermore, as we've long given up cable in preference of streaming services such as Netflix and locally stored movies and TV shows, this also necessitates having my desktop connected to the TV as well - yet another long cable, calling out to the adventurous anklebiter.  

The stack of devices also leads to a tremendous overall power usage, noise, and brightly glowing lights - primarily because I never remember to turn everything off.

I set out searching for a solution to this problem, a means to simplify the mess.  However, as has often been my experience with such things, each manufacturer makes a device very good at a couple things but terrible at everything else and, of course, locked down so I can't easily add or change functionality.  Game consoles come the closest, but they still lack functionality and customizability I want.

So, my solution: I'm building an Home Theater PC, or HTPC.  

My requirements:
  • Play DVD's
  • Play music and video from my local media library, but not require my desktop to be running at all times.
  • Stream music and video from any online source (Netflix, Hulu, Pandora, YouTube, etc, etc)
  • Have a fully functional web browser
  • Play games, from older emulated consoles to modern games
  • Be silent, or at least very quiet
  • Be economical - cheap to build, and consume as little power as possible
  • Present an easy to use, TV friendly interface.  No standard desktop under normal use.

What to get?

I wanted to run Linux on this - it's free! - but I'm trapped by Netflix, which won't stream 1080p without Silverlight (windows only).  So, as always, Windows it is for simplicity.  The upside to this decision is that the (currently free) Windows 8 Consumer Preview sports the Metro start menu, which (desktop PC issues aside) is actually a very ideal launcher interface for an HTPC.

To keep the size and power consumption down, it'll have to be a mini-ITX sized motherboard and have good enough integrated graphics to not require a discrete video card.  This puts us firmly in AMD's new "APU" camp - low power processors with surprisingly powerful graphics built right into the CPU.  Its a tough choice as to which to pick, weighing cost, performance and power consumption.  The Llano APU's come in 65w dual and triple core versions, and 100w quad core versions.  While the quad cores are obviously more powerful, a dual-core processor is really perfectly adequate for HTPC use.  That said, I do want to be able to do at least light gaming on this, so I think the oddball processor, the triple-core A6-3500, is going to be the way to go: The fastest of the 65w chips, and it sports an improved Radeon 6530 GPU, a substantial improvement over the dualcore's 6410 for a mere $10 premium. 

Toss in 4GB of RAM (Perfectly adequate for an HTPC, and only $20!), a 2TB hard drive (to go along with the 1.5TB drive I already have), and a standard DVD burner and we're good to go.  

So, my HTPC build will involve these bitties: 

Everything from Newegg because they are awesome, and purchasing from a single supplier saves on shipping costs.  Nobody else had everything I needed.
Apex MI-008 Case - As small as I could find, but still offering sufficient room for a couple TB of storage space for my local media library.  Otherwise, fairly plain and simple.
ASRock A75M-ITX Motherboard - Options are limited for Mini-ITX motherboards supporting FM1 processors
AMD A6-3500 APU - 65 watts, triple core, 2.1ghz.  The most performance I could get out of a 65w processor - important, as the 100w quad-cores would likely generate too much heat.
Pareema 2x2GB DDR3 RAM, a total of 3.5TB of hard drive space, and a random DVD burner.  

The computer itself - motherboard, case, ram, DVD drive and APU - come out comfortably under $300 - squarely in the price range of a game console, and with more power.

Next up: Unboxing and assembly!