DIY NAS: Hardware

I shall talk about all the hardware (minus HDD) in this post.

Before selecting or looking for hardware, we should list our requirements first. These are what I am looking forward to:

Low cost (Budget $450)
Low power consumption (less carbon footprint)
6 drive (in fact, the more the merrier)
Compact (ITX form factor)

If you want a NAS with 3-4 disk and not particularly concern about power consumption, then probably the old PC you have that is lying around could be turned into your faithful NAS.

If you want a "big" NAS with 6-8 disk, low power consumption NAS and have an old 4 SATA port PC lying around, you could underclock and undervolt to reduce the power consumption, and purchase a SATA expansion card. Or you could sell it off, and build a new one.

All in all, it depends on what you have, and what you want. For me, I do not have an old PC lying around, so I have to start from scratch. After some research, here is what I think would be fit my requirements.

CPU/Motherboard

NAS does not need really powerful processor, in fact, if it is just use for storing and retrieving data, we do not really need anything beyond Intel Atom or AMD Fusion processor. Unless you are planning to use it for something more than just feeding data, possibly a mini server or some sort, then probably you need a more powerful processor.

Ideally the motherboard should have a lot of SATA port so there is no need for us to purchase SATA card. SATA II or SATA III port does not matter, since the RAID setup might not even hit the SATA II 3 Gbps limit, roughly 357MB/s. However, having SATA III and high internal data transfer throughput is beneficial in healing the RAID. I have listed some motherboard which would be ideal for me:

Asus C60M1-I
6 SATA port, an uber low power C60 APU. Perfect.

Asus E35M1-I
6 SATA port, another uber low power E350 APU. Perfect.

MSI E350IA-E45
4 SATA port, same E350 APU as before. Great.

ECS NM70-I2
4 SATA port, low power Celeron 847. Great

Memory

Judging on our motherboard selection, max memory is 16GB, so I guess getting a single 8GB ram wouldn't hurt. If there is a need, we can always purchase another 8GB ram for our system. At this point, some of you may be wondering how much memory does commercially available NAS has, well, usually 1-2GB. Why so little? I have no idea. But basically, it depends on the NAS's OS.

Power Supply

The first thing about power supply that we should know is that there is a certification to power supply called 80 plus. There are different rating of 80 plus, which from a normal 80 plus to 80 plus platinum. Basically, certified power supply are at least 80% efficient at converting AC from your wall to the DC that our computer uses. If you are really green, you may considering getting one that is certified.

As for the rating, lets use Seagate drive for calculation (see previous post, 8W). 6 Drive at 8 watt each is ~50 watt. Processor + Motherboard + RAM = ~100 watt. We need a power supply that is at least 150 watt to be on the safe side.

Casing

Casing is pretty much like our skeleton, a well-designed casing will not only keep our component cool, but also makes our maintenance and upgrading life easier. Hot-swap or no hot-swap? IMHO, if you build a 6 drive NAS, and decide to start with 3 drive, how many times do you need to open the casing for upgrading? 3 times, if the NAS is good and healthy throughout its life. So, my take is, it is not a necessity, but good to have. Bottom line, we should try to get something decent. Here are a few that caught my attention:

Fractal Design Node 304

3.5" HDD Bay: 6

Hot-swap: No

Dimension: 250 x 210 x 374 mm

Lian Li PC-Q18

3.5" HDD Bay: 6

Hot-swap: 4 (Weird.. why only 4? No idea..)

Dimension: 411 x 271 x 323 mm

Fractal Design Array R2 Mini ITX

3.5" HDD Bay: 6

Hot-swap: No

Dimension: 250 x 200 x 350 mm