Tuesday, December 4, 2012

Low power NAS/File server build

Hello folks! I am here today to share a new computer adventure! Two months ago, pushed by the desire of getting rid of one the old energy-inefficient computer that I used as a NAS, I started to explore the possibility to upgrade to a newer, faster and more thrifty (in terms of watts) configuration.

At the beginning I thought I could just replace one or two parts, but then I quickly realized my better option was just to take no prisoners and thrash all the parts that I had except the uATX microtower case and the external USB drives.


The old computer I am talking about was a HP Compaq Dx2000 Microtower based on a 3 GHz Pentium 4 CPU and equipped with:
  • four salvaged DIMMs running at different frequencies and of different capacity, for a total of 3,5 GB of unstable RAM,
  • a small and noisy 40 GB Maxtor HDD that my self-preservation instinct said was going to fail without even reading its SMART data,
  • a dirty cheap TP-Link 32-bit Gigabit PCI Network Interface Card I bought one year ago to replace the painfully slow Intel PRO/100Mbps integrated NIC,
  • of course no CD-Rom,
  • of course no floppy drive.
When I took the motherboard out of the case of this PC and made it run on my desk I saw that the Intel 865GV Northbridge (circled in red on the next picture) was getting so hot I could cook eggs on it, while the Intel ICH5 Southbridge (circled in yellow) stayed much cooler.
Old ATX motherboard with Pentium 4 CPU (green), northbridge (red), southbridge (yellow) and IDE (purple)
Also I noticed that both the CPU fan (circled in green) and the power supply unit (PSU) fan were very noisy and that I had no SATA data connectors, but just IDE (circled in purple).

Furthermore, and that confirmed my feeling, the Maxtor HDD (circled in yellow on the next pic) was making a funny clinking noise that I could hear over the sound on the chassis fan sitting next to it (circled in red).
IDE HDD (yellow) and chassis fan (red)
Not to talk about the power consumption which was steadily at more than 180 watts 24/7... probably due also to the uncertified 250 watts PSU and its 80 mm fan. This PSU had two rails:
  •  one +5V and 20A rail which corresponds to (you can do the math) max 100 watts
  • one +12 and 15A rail which corresponds to max 180 watts
250 watts PSU
So I decided I did not want to keep this PSU, and for two reasons:
  • it had no SATA power connectors at all, and I was going to need it for my disks
  • its efficiency range was higher than the actual power I was going to draw with the configuration I planned to build;
In fact, the energy efficiency of a PSU drops significantly at low loads and its efficiency generally peaks at about 50–75% load. I found good explanation of this on Tom's Hardware and in a post by JonnyGuru on Anandtech.

As I said before, I decided to keep the three external USB disks that I had for a few years to store my data in three copies. These three disks are a Verbatim 2,5" 350 GB/5400 RPM (circled in yellow below) and two 3,5" Western Digital, one of 500 GB/7200 RPM (circled in green) and one of 2 TB/5400 RPM (circled in blue). Till then, they were externally connected to a USB hub equipped with a small PSU to guarantee electric current stability to the whole bunch. But that was going to change, as you will see later in this post.
The three external USB HDD
As you can expect, upgrading to a last generation motherboard was going to bring great change: I was going to definitively say goodbye to the old fashioned blue BIOS I had been so used to see. Anyhow I wouldn't be probably missing those "CMOS setup utility" or "American Megatrends Inc" more than a few seconds. Just the time to say UEFI.
In the next picture you can see the CPU temperature and FAN speed on my old Pentium 4, as well as the voltage on each rail and the CPU VID:
BIOS hardware monitor

Let's start to say that I didn't want to spend any money on the chassis, so I cleaned up the one I had from all the dust and spider webs and decided to buy an ATX motherboard that would fit in it. In any case my plan was to keep my computer passively cooled in the three following ways:
  • the first one was to keep the computer in the basement, which is pretty cold (around 10°C in winter and less than 20°C in summer),
  • the second one was to underclock the CPU I was buying, in order to produce less heat and reduce the need of chassis fans to dissipate (which by the way would also reduce the general power consumption because each of these fans drew up to 3 or maybe 4 watts),
  • the third one was that I was going for an external PicoPSU, as I will explain later on.
Recycled old computer case
So now, let's talk a little about the parts I went to buy. As I said I decided that I wanted an ATX motherboard, also because I wanted a bit of scalability (which is the main advantage of this motherboard factor over a Mini-ITX). My choice was the MSI Z68MA-G43 (circled in yellow on the next picture), which was to me a pretty cool product for several reasons:
  • above all its price, very cheap at 50 dollars
  • the CPU socket is LGA 1155
  • 4 x DDR3 slots for up to 32 GB
  • 4 x SATA 3Gb/s
  • 2 x SATA 6Gb/s
  • 4 x USB 2.0 ( plus 8 onboard USB)
  • 2 x USB 3.0
  • 1 x HDMI 1.4
As a general information, this motherboard brings great scalability because the LGA 1155 socket accepts any Sandy Bridge processor from the Intel Celeron G440 to the Intel Core i7! And the four DDR3 slots accepts up to 32 GB of RAM, which is enough to host a full vSphere lab with a few virtual machines. In a few word, such a motherboard it's good for a NAS, it's good for a HTPC (it has one HDMI 1.4 port and six audio ports), and it's good for building a virtualization lab!

For the moment, being my only will to build a low power consumption NAS, I bought this motherboard in conjunction with an Intel Celeron G530 (circled in green), which is still now one of the best low cost microprocessors out there (around 50 bucks on Newegg). And it is capable of decoding HD movies, so it is all you need if you want to use it in a HTPC.
Note that there is no need to buy the G530T which is more expensive. In fact, even though Intel says that the 500-series variants ending in 'T' have a peak TDP of 35 W, while the others 65 W, the G530 is easily underclocked in just one click from the MSI UEFI BIOS.
Note also that the G530 came with no thermal-paste, and this is because you don't need it.

Regarding RAM, I went for one G.Skill Ripjaws-X DDR3 (30$, circled in red). This SDRAM was compatible with Intel LGA1155/LGA1156, so all was well. Having bought just one made me loose the Dual Channel functionality until I will buy another one, but I did not care because high-end performance is not what I was aiming to.

To complete this nice configuration, I bought a SSD drive (circled in purple), and, believe me, this means steroids for my PC.

Solid State Drives are to me the most impressive evolution in home computing since ever, even greater than the shift from floppy drives to cd-roms. This disk is told to be dramatically fast and reliable and my MSI motherboard had the required SATA3 interface to get the maximum from it. I'll talk later about the performance of this disk, but know that no upgrade is a real upgrade if you don't get an SSD disk!

The disk I choose is a Crucial M4 2,5" 64 GB SSD, whose capacity is more than enough for hosting any Windows operating system and its paging. It was still a little pricey (74$ in november, which is a bit more than one dollar per gigabyte...) but I wanted one at all costs!
New mobo, proc, RAM and disk

Unboxing the MSI Z68MA-G43 (G3) motherboard

MSI Z68MA-G43 (G3) top view

MSI Z68MA-G43 (G3) external connectivity view

Unboxing the Intel G530 Celeron processor. No thermal-paste.

My 8 GB G.Skill DDR3
In the next picture you can see my Crucial M4, which is said to have the following specs:
  • Sustained Sequential Read: Up to 500 MB/s (SATA 6Gb/s)
  • Sustained Sequential Write: Up to 95 MB/s (SATA 6Gb/s)
  • 4KB Random Read: Up to 45,000 IOPS
  • 4KB Random Write: Up to 20,000 IOPS
Unboxing the Crucial M4 64 GB SSD drive (view from top and bottom)
As I mentioned before, I wanted to get rid of the standard power supply unit because I thought that
  • normal PSU have low efficiency at low current consumption
  • normal PSU are noisy
  • normal PSU get hot inside the case
  • energy efficient PSU are expensive
I recently discovered that a new kind of PSU existed that fitted my need for a low consumption NAS. These were called PicoPSU (which by the way is a US patent).

The model I decided to buy is a Mini-Box PicoPSU-90 DC/DC (90 Watt) that you can see circled in yellow in the next picture.

The power brick beside is a generic 19V AC/DC converter (similar to those used for laptops but with a different voltage - circled in blue in the next picture) that must be bought as well. The model I choose is a 84 watts LS-PAB90 which delivers 7 amps max at 12V.

Here's the three little problems you will probably encounter buying a PicoPSU:
  • the PicoPSU motherboard connector has just 20-pins, while many ATX motherboards have 24-pins,
  • this internal small DC/DC PSU is designed for Mini-ITX motherboard so there's a good chance that the 4-pin 12V CPU cable will be too short,
  • the external AC/DC converter will probably sold without the classis 3 wires C5 connector power cord, so the plug receptacle (circled in red) will be empty.
PicoPSU and external power brick
The first problem, as you can see in the next pic, is that my PicoPSU has 20-pins only. The solution? Simply don't worry if your motherboard has 24-pins connector because the PicoPSU fits perfectly in it leaving the four last pins empty. I can confirm that the four extra pins are unnecessary.

20-pin 90W PicoPSU, small isn't it?
For the second problem, being those PicoPSU designed for mini-ITX motherboards, the CPU P4 cable might be too short for you, and in this case you need to buy an extension, which is what I did...
4-pins 12V CPU cable, too short...
Here's a picture of the mentioned extension, which I paid 6 dollars:
BitFenix Alchemy 4-Pin ATX12V extension
For the third problem, just get any 3 wires Mickey Mouse power cord. Just think to it beforehand or you will find yourself stuck waiting for this cable being delivered to you...

Then here's a picture of the DC/in power cord which goes from the power brick to the PicoPSU:
External power brick to PicoPSU cord
So, let's go on with the assembly. As you can see in the next picture, and I was surprised of it, once I plugged the power brick, I discovered that a few watts got continuously wasted in heat even if nothing was plugged on it, which was quite deceiving. I must admit this was a basic AC/DC converter that I paid only 40$, so no surprise it was made in China with low cost resistors and diodes. If I had followed JonnyGuru's suggestion, I should have probably bought a highly efficient 'wide' PicoPSU, where the term 'wide' is used to indicate those PSU that accept a wide input voltage range, but the price to pay was higher than what I planned for.
Wasted watts...
That's all for the PSU topic for the moment.

Guess now what I did with the three external USB drives. The answer is simple. I tore them open and found inside each of them a standard SATA disk, that is exactly what I expected.

The first was a 2TB Western Digital Caviar Green whose specs are:
  • model: WD20EARS
  • year of production: 2011
  • interface: SATA 2
  • capacity: 2 TB
  • speed: 5400 RPM
  • cache: 64MB
  • power: 5V * 0,7 amps and 12V * 0.55 amps
2TB WD Caviar Green disassembled
The second disk was a older Western Digital, whose specs are:
  • model: WD5000AAKS
  • interface: SATA 2
  • capacity: 500 GB
  • cache: 16 MB
  • speed: 7200 RPM
  • power: 5V * 0,68 amps and 12V * 0.55 amps
500 GB WD Caviar disassembled
The third disk I disassembled was a Verbatim. Actually when I opened it I found a Samsung HM320JI repackaged as a Verbatim drive. Its specs are:
  • size: 2,5"
  • interface: SATA1
  • capacity: 350 GB
  • cache: 8 MB
  • speed: 5400 RPM
  • power: 5V * 0.85 amps
Verbatim 350 GB 2,5" disassembled
When I mounted all the parts I bought together, that's what I got: an Intel G530 (circled in green), running atop of a MSI ATX motherboards with Z68 chipset, with 8GB of DDR3 (circled in red) and a small, fanless, silent PicoPSU (circled in yellow).
New mobo, CPU and DDR3 plus a PicoPSU
In the next picture you can see the new 6 SATA ports. The two white ones are SATA 3 (perfect for my Crucial SSD), while the four black ones are SATA 2 (perfect for my three disassembled USB HDD).
MSI Z68MA-G43 SATA ports
In the next picture you can see how I got those four disks (circled in blue) screwed into the case. They are now sitting in the top of it, each kept in place by one screw. Actually the PicoPSU comes with just one Molex and one SATA connector, so I had to buy a SATA Daisy chain splitter to allow for up to four drives to be powered. The red cable circled in yellow is the P4 12V extension for the PicoPSU to the CPU.
How to fit four disks in a small case
Now, here's a few pictures of the new MSI Click BIOS II, which I liked very much, especially if compared to the old BIOS you saw before. This UEFI BIOS can be managed by keyboard or by mouse. It shows important information (such as temps and fan speed) and allow for a quick overclocking/underclocking of the processor.

When I first powered on my new NAS, what I did to reduce power consumption was to
  • select the ECO mode,
  • set the CPU smart fan target to 50°C,
  • set the CPU min. fan speed to 0%, which in my configuration corresponds to around 1000 RPM.
These settings is largely enough to keep my computer cool and in case the CPU temp rise above 50°C the fan will start back spinning as fast as it can.

To be true I also tried to disconnect the CPU fan, which is normally not the best solution. But I was positively surprised to see that, once underclocked, the G530 stayed cool at 65°C-70°C even under the load of OCCTPT or Prime95 without a fan! In the end, I connected this fan again, just to be safe, but, again, know that if you keep your NAS in a cold place (such as a basement) the Intel G530 can live happily without any active cooling.
My fan settings...
In the next picture you can see how I underclocked the Intel G530. Always in ECO mode, I set its multiplier to 16X, which is the min possible value and the speed of the bus to 100 MHz. So the final CPU frequency was 1600 MHz and the voltage gets lowered automagically.
Underclocking the Intel G530
I also enabled the Intel C-State. This is a technology by Intel which allows the operating system to independently lower the frequency of the cores when it is almost idle.
Intel C-State
In the next picture you can see the power consumption of my system when it was shut down. Roughly 6 watts.
Power drawn by my NAS when shut down
When I turn it up, my NAS, which is installed with Windows 2012 and four drives (1 SSD, 2*3,5" SATA2 and 1*2,5",SATA2), it draws up to 77 watts. The picture shows 74 because I wasn't able to get the peak load with my camera when it hit its maximum. What is important here is to understand that my 90 watts PicoPSU and its 84 watts external power brick are able to manage that load without flinching! I tested this many times and all of my hard disk drives were able to spin up, so cheers to me.
Peak power consumption when the computer boots
Now, for the idle power consumption, which is what most of you should be interested in when designing a NAS, my build goes down to 33/34 watts under light load: I was actually watching a movie streamed through PS3 Media Server and the actual .avi file was stored on a secondary drive, so there were two drives up and running and two sleeping. Not that bad, isn't it?
Power consumption with PS3 Media Server
When the computer completely idles, it stabilizes at around 29 watts! Much much better than the 180 watts I had with a old Pentium 4! I don't believe that with an Atom processor or a AMD Fusion I could have been able to do better than that.
NAS idle power consumption down to 29 watts! Personal best!
In the next screenshot you can see temperatures and voltages of my NAS build as showed by CPUID Hardware Monitor. As you can see both the CPU and the disks run at very low temperatures, mainly due to the fact that the basement is pretty cold in winter. Now you might wonder why there are only three disks shown in the table when I have four... The reason is that the Crucial M4, having no moving parts, has no need for a temp sensor, just like most of the SSDs out there. So the three disks shown are the two Western Digital and the Verbatim/Samsung.
CPUID hardware monitor
If you are curious about the performance of this build, just know that Windows 2012 got installed in less than two minutes (yes, you read well: two minutes! I was speechless!!!), and it boots in less than three seconds. I was able to install Adobe Reader in less than a second and PS3 Media Server in less than 3 three seconds. I'll probably publish a little more data about this NAS performance in a future post, so stay tuned!

So that's all for this upgrade!

I have tried to be as much clear as possible, but it was a long and interesting topic to write, so forgive if sometimes you find the writing a little messy. Also do not hesitate to share your opinion on this build or to ask questions if you are planning to go the same road. I'll be happy to give details and tips to anybody asking!


Perf test 1
Perf test 2
Perf test 3 - how I improved my SSD performance 


  1. This is a great post! It is in fantastic detail, I will no doubt be reading it many times as I am trying to achieve the same sort of thing. Thank you!

    1. Thanks for your positive comment! If you have any question do not hesitate to ask.

      I take the chance to share a little bit more detail: when I passed from IDE to AHCI mode, my power consumption went from 29 watts to 26 watts! Nobody else as ever reported this so I thought it could be an useful information to share.

  2. Thanks for this interesting guide. I'm trying to build a nas using it buy don't have a case. I want to hold around 6-7 HDs. Any ideas?

    1. Thanks Cos P.

      Make sure you have enough SATA ports on your motherboard and that you have enough power connectors to get them spinning (you could make use of Y split cables or daisy chains if you don't have enough power connectors).

      My MSI mobo has two SATA 6GB/s and four 3 GB/s. I am telling you this because you must figure out what you need and the kind of RAID you're going to make before buying.

      If you are buying SSDs, you can buy them in 2,5" factor (the laptop factor) and they'll take no room inside your case/ The price should be the same.

      For 6-7 HDD, have a look at the Thermaltake Element S Mid Tower:


  3. Truly a great report. I was looking for such a setup for some 30 minutes now. But on Google you will find a lot of old reports and may of them just claim to be low power computers (which they just might be), but often the actual consumption is not measured.
    This is perfect and it proves that I does make a lot of sense for me to invest in such a nice pc (file server).

    1. I am glad you found this post useful!!

      Please let me know what mobo and CPU you'll buy in the end and share its power consumption!



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