The CPU / Motherboard is the backbone of your NAS. We have to be picky on this one. Ok, I need something that is cheap, powerful and energy efficient. In chinese: 又便宜又大粒还几漂亮! (malaysia ascent). Just like below =D
Hello! this is a NAS blog, not adult blog, come back JTSF!
Right, we have quite a few features to consider carefully:
1. To make our NAS compact, the size has to be Mini-ITX.
2. I need as much SATA ports onboard for scalability. Ideally 6.
3. SATAIII 6Gb/s is good to have, not a must. Typically, the bottleneck is on the HDD itself and not the SATA port.
4. For scalability, the motherboard should support up to 16GB of RAM. You may feel this is overkill but you will find out later when we discuss about RAID.
5. The energy efficiency of your build will highly rely on this component. I need to find the right balance - a processor capable enough to serve as a NAS (or more) and yet power efficient when paired up with the motherboard.
6. Gigabit Ethernet - all modern motherboards support this and should not pose a problem.
The components of the NAS are closely dependent on each other. Choose wisely or you will be constrained by the deprived feature later on. My studies also reveals that an onboard processor would lower the power consumption of the system. In contrast, socket-based processors are TDP 35W on average, a tad higher than onboard processor. It also increases the total cost when paired with a separate motherboard. It is clear that my choice will be a motherboard with integrated processor.
1st Candidate - ASUS E35M1-I
After some hunting, I first set my eye on ASUS E35M1-I
2nd Candidate - MSI E350IA-E45
The lost hope of a perfect NAS board make me scout SLS (IT Mall). I chanced onto MSI E350IA-E45 displayed at one back alley shop. It offers similar specs to ASUS E35M1-I.
3rd Candidate - Gigabyte GA-C847N-D
At this point of the search, I was getting a little lost; having cross thoughts of getting a socket based processor & separate motherboard. I reviewed my requirements once again and restarted the search, this time staying away from AMD E-350. From the stacks of pricelists I've collected from SLS (IT Mall), there is Gigabyte GA-C847N-D.
PCI expansion slot. I needed this expansion slot to scale to 6 HDDs in total and the performance of my NAS must not be constrained by a 133MB/s shared bus. Wake up Gigabyte! It is 2013 now! Are you are still living in Millennium 2000?
Reviewing Intel Celeron 847 - NM70
Reading these reviews helped me made up my mind to get one of these NM70 boards:
Guru 3D reviews Intel 847 NM70
Madshrimps reviews ECS-NM70-I2-V1.0
Xbitlabs reviews Celeron-847
Madshrimps reviews BIOSTAR-NM70I-847
German Hartware.net Compares 4 different platforms of low power motherboards
The Computing Power of Intel Celeron 847 - NM70
Let's take a look at the processing capabilities of Celeron 847
Source: CPUbenchmark - Intel Celeron 847, 1.10GHz
Source: Guru3D - Intel 847 NM70 Performance
Source: Xbitlabs.com Celeron 847 Computing Performance
Power Consumption of Intel Celeron 847 - NM70
Next, we compare the power consumption between Celeron 847, AMD E-350 & Intel Atom 2700
I am contented to have 21W idle. The choice is clear now. =)
4th Candidate & the Chosen One - ECS NM70-I2 (V1.0)
The final choice is narrowed down between Biostar NM70I-847 and ECS NM70-I2 (V1.0). Both boards offer similar specs - nice processor, low power consumption, supports up to 16GB of memory. The only downside is 4 SATA ports onboard. To scale to 6 HDDs, I would need to add a PCI-Express SATA card. Any of the first few cards on sales here will do the job.
TDP - Thermal Design Power; Wiki - List of CPU Power Dissipation Figures