SPCR

Hi,

I see the fitpc2 is <10 watt, and by looking around I can not see how to achieve these numbers in a DIY project.

Does anyone have kill-a-watt results for the fitpc, including disk? (idle, load).

My main focus is to have an "always-on" box running 24/7, so the idle consumption is very important. I have an iomega NAS with an ARM-cpu and modded with optware, but kind'a lack an FPU to do some transcoding too.

In the forum I see a lot of 20+ watt DIY solutions (with "apparently" same specs as the fitpc), so *how* can the fit-pc get below 10 watt still puzzles me.... Please redirect me if I have missed any <10 watt DIY projetcs!

Kind regards,
/Thomas

You need mobile parts, and really underpowered and/or good ones at that. And the good ones aren't cheap.
It would probably be more practical for you to have a dedicated box for transcoding you can wake up from your 24/7 ARM box with WoL.

I've never seen anyone build something with similar specs as the fitpc. Its hardware is kind of unique (US15W chipset). You should be able to achieve or eve beat that kind of idle power consumption with mobile gear. So your DIY project would have to involve ripping the innards of a broken laptop or something. The later Mac Minis built on mobile C2D parts apparently got under 10W idle as well. I don't recall anyone posting about a build based on similar parts as the Mac Minis either (it would be expensive).

Im not sure you could reach lower than 10W idle with a good transcoding setup. Im idling 14-15W with my setup atm, Mini ITX Low Power Build, but im runing 3 fans and dual ram sticks, so i guess you could lower it more, not sure if you could reach sub 10W idle though.

What i would do differently over my setup trying to lower it even more is (not sure if it will be significant enough dip down around 10W)

- PSU
I would probably try with smaller PSU like Premium picoPSU-80/6.6A 80W AC-DC or the JonnyGuru recommended Combo PicoPSU 120-WI-25 + FSP120-AAB 19V power brick.

- CASE
Lian Li Q11 is a nice case only uses 1 frontal fan, and its position will be right next to the CPU, check the following thread, mATX mobo in Lian Li Q11 mini-ITX build. I would try to go as minimal fans as you can, i would swap the included case fan for Noiseblocker NB-BlackSilentPro PK-1 140mm x 25mm Ultra Quiet Fan - 700 RPM - 9 dBA and undervolt it.

CPU Cooler
Although an overkill, the Thermalright HR02 performs really well with very minimal airflow and the Q11 is wide enough to allow installation of it (check the thread above for pictures), and the fan placement will allow the case fan to cool the cpu also.

- Memory
Only go 1 memory stick, maybe lowest voltage you can find. I went with Kingston Lovo 1.25V, still cant get the intel mobo to allow to use that voltage.

- Mobo
Intel is rumored to produced the most efficient mobos, i would just go with Intel DH67CFB3, and turn off via bios all the stuff you wont use (up to you, but for example Serial Ports, Parallel ports, Audio card, 3rd party Sata and USB). Or maybe MSI, also has good record on efficiency, maybe will allow you to tweak voltages more than intels.

- CPU
Complex thing here, as you want a capable transcoding CPU, if you benefit from hyperthreading i would go with Intel Core i3-2100T Sandy Bridge, but if you don't, probably a Intel Sandy Bridge Pentium G620T, but they do have some stuff disable, like Intels Quick sync that could help (depending on the software) with transcoding.

- HDD
If 500GB is enough for your storage needs, i would go with Hitachi 5k500b, it has been review here in SPCR very favorable, very low noise and power consumption. Or if you dont need that much space maybe an SSD, here is wierd cause not all websites grade equally, but in average Samsung 470, Intel X25m and Kingston V100+ are among the lowest consumption SSDs, stay away from OCZ Vertex or Sanforce based SSDs.

I still dont know if you will able to dip into 10W barrier, i personally doubt it, but you might get really close. If the sub 10W idle consumption is that important, i would probably wait for Ivy bridge with the die shrink we might see what you want possible with the successor of the 2100T/G620T.

Power supply - the PICO is fine.

Case - you want small minitower case with the side removed entirely. Place it on its side so that the heat has at least 2-3 ft of airspace to radiate into. Technically all you really need is the mounting chassis from the case and the power switch. You could as easily stick it all in a wood box or leave it bare like a typical tube amplifier usually is. Without the power supply or a video card in the equation, there's no reason really FOR a case other than aesthetics.

The CPU cooler should be a big beast - it'll stick out of the top of the case. So be it. If you do it right, it will radiate up to 30W total before causing problems. Yes, the CPU cooler will be enormous. So be it. Note - you want as widely spaces fins as possible if you are going completely passive. I like Scythe, YMMV here. Only some coolers are really designed for passive operation as an option.

The motherboard/CPU should be a dual core processor - chose anything with a low heat profile of less than 30W and you should be fine.

Any lower power laptop drive will suffice. If it's on the other side of the chassis or on a tray off to the side, it will contribute 0 degrees to the rest of the machine.

It's a different approach, but I'm thinking that your main issue here is noise and reliability and not actual power limitations. 0db is completely possible this way. Basically it'll radiate less heat than your LCD TV or your amplifier, which are designed as well to operate passively. You should be able to get all of this to run within 20-30W or so, which is a few pennies a day. Trying to get less that that and you run into serious problems that cost a lot of money to get around. The advantage of this approach is that it's very inexpensive.

To get the fitpc2 power level you need fitpc2 level hardware:
MSI IM-US15WP
The mainboard has a 1.6GHz Atom with an ultra low power chipset and 12V in port. It's completely fanless, just a very small heatspreader on the CPU and chipset. Add 30 watt high quality power brick and you should get the 10 W figure.
Best price for the board I found was 300+€!

A much cheaper option with similar hardware to the MSI board above is the Intel D945GSEJT :

http://www.intel.com/products/desktop/m ... erview.htm

I've run one of these for a while now - typical operating power draw is 11w with a Samsung 320gb 5400RPM laptop drive and a single 2GB SODIMM, using a 60w FSP brick. It's not particularly fast, but it can support pretty much any OS and can run fanless.