Right, due to newborn arriving, I haven't really been able to get this going until today. I put the system together with the following hardware:
Case: Node 304
Mobo/CPU: J800N-D2H (J1800 dual core Bay Trail processor running at 2.8Ghz)
Memory: 4GB 1333Mhz (1.35V SO-DIMM, will upgrade to 8GB if needed for Arch VM)
SATA controller: 4xSATA KALEA-INFORMATIQUE PCIE 1x
HDDs: 2 x 3TB Toshiba HDD (5900rpm drives, the Toshiba 7200rpm drives offer better performance and are 5 euros cheaper, but consume more power and are louder)
SSD: 120GB Crucial M500 (not in the array, will run Arch from it)
First off, the most important thing for me when putting this together is that (in order) it runs silent, consumes very little power and that has decent performance. The case looks fantastic with a brushed metal finish. It's also quite small so it sits under the TV. It has space for 6 3.5" drives and it comes with 3 fans. As the system is so power efficient, I only connected the 140mm fan and it's inaudible from 0.5m away.
The mobo/cpu offers impressive performance for the price, and as it's passively cooled, so there's no extra noise. As you can see from the picture below, at the moment it's doing a parity check at 135MB/s, so it's no slouch. It also has decent integrated graphics and video/compressing extensions, together with VT-x, so it basically offers a lot in a small package. And ofcourse, it has a TDP of 10W for the full mobo/cpu, so it's very power efficient. I can't tell you exactly how efficient it is as my kill-a-watt meter decided to die recently, but I'll get another one soon and post some results. One thing about this mobo, it comes with BIOS version F2, which does not support Unraid or pretty much any other linux distrubition (or Windows 7), so to get it to work, you need to upgrade the bios to version F3 as detailed here. Once that is done, Unraid works very well.
As for the HDDs/controller, the mobo only supports PCIE 1x (2.0) which gives a total bus speed of 500MB/s, which together with the 2 Sata ports on the mobo is enough for me as the case only supports 6 HDDs in total. I'm starting with 2 Toshiba 3TB HDDs (although weirdly, on the GUI it shows as 1 being a Hitachi for some reason...). I chose them because they were on discount, 90 euros each (which is around $125). They have good reviews in terms of reliability, noise and power efficiency and are much cheaper than the 3TB WD Red drives. I will be getting a 3TB WD Red to run as the parity drive soon. I plan on getting more drives as needed together with the Unraid license. In addition, I also have an SSD which I will be running an Arch VM from. It will not be part of the array as I don't want it to keep the disks spinning unnecessarily.
Here it is formatting and running a parity check on the drives:
Will update when I get the kill-a-watt meter.