Posted by virantha on Mon 26 January 2015

Building a low-power home file server using Intel's Avoton platform

In this post I'll detail the hardware I used to upgrade my 2 year old home server that was getting a little bit long in the tooth. I wanted to replace a Core i7 based XenServer host connected to an external 8-bay SATA enclosure that had an idle power consumption of over 100W for machine+enclosure with all drives spun down. In my new build, with 8 hard drives and 3 SSDs, I can get it under 40W with drives spun down but the system awake.

1   Getting the components

Here's the list and summary of each part. I have more details and options listed in the next section.

File-server components
Component Retail Paid Comments
$309 $223 @ newegg Mini-itx 12 SATA ports (!), quad-core Intel Atom 14W TDP CPU
$149 $149 Supports 8 hard drives with hot-swappable trays (only 2x molex power connectors for all 8 drives) plus 4x 2.5in drive cage. SFX power supply required.
$20 each ~$15 @ newegg wih twin pack PWM (4-pin) so speed is controllable and reportable via BIOS. Very quiet and high CFM and pressure
$84 $84 Used a single stick and will upgrade later. Important to note this is server memory with ECC support and 1.35V (low-voltage) vs standard 1.5V
$55 $55 SFX form factor. Temperature controlled fan that stays off under 50W load in typical usage. Non-modular
$2.50 $2.50 Good length for this case/MB, and locking latches and good build quality

1.2   Motherboard

I went with the new Avoton series of server boards based on the Silvermont Atom platform (the passively cooled CPU is soldered onto the motherboard). These are surprisingly capable and extremely low power. For example, the 4-core ASRock C2550D4l mini-ITX motherboard has 14W TDP, and is usually under 10W. This server-class motherboard has no problem playing back my high-bit-rate 1080P Plex streams, and supports 64GB ECC RAM (regular RAM also works), 12 SATA ports, and has an IPMI interface. IPMI uses a dedicated ethernet port and lets you get a console via a web interface over the network, letting you physically place this machine anywhere you like and do everything without a keyboard and monitor. You get access to all the sensors, BIOS, and even BIOS updates through this web interface, which makes everything hassle-free, and makes me wonder why I didn't splurge for this feature years ago.

If you're planning on doing any kind of virtualization or multiple Plex streams, then I recommend jumping up to the 8-core version, the ASRock C2750D4I.

1.3   Case

I decided to go with the new NAS desktop DS380B case from Silverstone that has a built-in 8x3.5in bay hot-swappable backplane, plus an internal bracket for mounting up to 4x2.5in hard drives or SSDs. It comes with 3x120mm fans that are relatively quiet, but I upgraded to 3 [amazon B00C249PEO Corsair SP120 Quiet fans] that support fan speed control via PWM and also report RPMs to the BIOS.

1.4   Memory

Here is a list of all the Kingston memory that will work with this board: Kingston ECC memory I decided to pay the slight premium for a stick of ECC low-voltage RAM.

See this article for the benefits of using 1.35V vs 1.5V RAM. You'd probably end up saving about 1 to 2W on a 16GB system, or almost 10% on a ~20W TDP system like the Avoton.

1.5   Power supply

I originally considered getting a PicoPSU-160-XT with 16A brick, but the power brick was sold out, and I wasn't too keen in the end on running the 12V directly to my system. Plus, it was tough to find an adapter plate to have a nice DC-plugin come into the case. Moreover, I was looking at combined over $100 for this combination, so I ended up settling for a 300W power supply that's fanless under 50W draw from Silverstone listed below. I probably could've saved a few watts with the PicoPSU with a good adapter, but this was the easier solution. Keep in mind that the Silvestone DS308B NAS case uses a SFX form-factor power supply, like this power supply, and not a standard ATX sized power supply.

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