Part 2 – Chipset Selection
For my first NAS box, I just went with what I knew. I had built a Linux desktop based on a core2 duo Asus mobo and I just got the same hardware for my NAS because it worked well. Times have changed, Linux is now compatible with a wider selection of modern hardware and this project has a “energy efficiency” that influences the processor architecture selection.
My only limited experience with the all too popular Atom processor was unsatisfying (a short lived purchase of a netbook who’s anemic performance prompted a rapid return to Costco). Yet looking at the commercial NAS offering, the vendor I looked at (Qnap/Synology) used the Atom processor for their high end boxes.
I also had very little experience considering low power consumption or what components contributed to it the most. A little research was in order. For all things NAS, my first stop is always the excellent website: SmallNetBuilder.com. I quickly came across a review of the Synology DS1010+ from which I got the following info:
DS1010+ review / hardware specs:
- Atom D510 (1.66Ghz)
- Intel’s ICH9 southbridge. (supports 6 SATA disks) — Article says ICH6: must be a typo.
- Has 1Gb of DDRII SODIMM RAM (laptop RAM)
- An empty SoDIMM socket for RAM expansion
- A 128MB flash module (to boot the system software)
- VGA port for console
- 2 Intel 82574L Gigabit Ethernet controllers
- 4 USB 2.0 ports
- A Silicon Image Sil3132 PCI Express 2 port SATA II host controler for the single eSATA port to connect to the expansion box (DX510).
A little more poking around the NAS reviews on SmallNetBuilder reveiled a review of the DX510 expansion unit:
DX510 review / hardware specs:
- Houses up to 5 SATA disks (3.5″)
- It uses a very popular SATA port multiplier Silicon Image SIL3726
- While theoretically, using a port multiplier slightly diminishes the maximum throughput of a disk array, the actual test numbers show that you would be hard pressed to notice any difference.
Note on SATA multiplier:
The DX510 expansion module uses a port multiplier which is essentially using a single eSATA connector to link the NAS SATA adapter to a SATA multiplier (multiplexer) in the expansion box. In this setup, the disks in the expansion box appear to the NAS as if they were hosted in the NAS, directly connected to the NAS SATA controller. This provides an easy and modular method to expand a NAS box with a small theoretical performance compromise. Here are some links with more info on SATA port multipliers:
Note on the silicon image sata controler:
The Sil3132 is extremely well supported on Linux and is fully compatible with SATA multiplier. There are various providers of SATA host adapter and multiplier chipsets but my brief research concludes that Silicon Image seems to be the most popular, most reliable and most compatible under Linux. Important: Before selecting a motherboard or SATA host adapter card, review carefully what chipset is used. Older chipsets will likely not work with port multipliers because the standard probably did not yet exist when those chipsets were designed.
Armed with this new info about the chipsets used in the DS1010+ and expansion unit, I figured: If it’s good enough for Synology’s fastest box, it’s probably good enough for my home setup. There are other low power chipsets available that could work quite well but at least, I had one “known” working solution in hand.
I briefly looked at other possibilities using a core i3 which can be fairly low power but also much faster than an Atom processor or some low power CPU from AMD but the corei3 I had my heart on the Synology recipe.
The Hp ProLiant MicroServer
There is another VERY VERY NICE platform out there which I considered for a long while: The HP ProLiant MicroServer also known as HP ProLiant N36L. It is an elegant NAS box based on a low power AMD CPU (which is reportedly almost 20% faster than the Atom D510). It hosts 4 hot swap SATA disks, a CD/DVD unit, has a USB connector on the mobo (if you choose to load your software on USB instead of wasting a disk). It’s fairly cheap ($320 at Newegg) and Linux compatible. The reason I did not go that route was mostly that I wanted to build my own from parts. There were a few hiccups that also contributed to not choosing that platform for my project. The built-in eSATA is not compatible with port multiplier and the ethernet chipset is not from Intel (which seems to make the highest performance, most Linux compatible ethernet). Both issues could have been remedied using the two free PCIe expansion slots.
Here is a summary of this fine box with some links to reviews, specs and photos in case you choose to explore this avenue for your own project:
- Linux / Ubuntu compatible
- PC3-10600E DDR3, max 800 MHz (comes with 1Gb, can be 4x4G=8G) Unbuffered ECC
- 1x 5.25″ bay
- 4x RAID bay with tray
- 1x Esata port (does not support SATA multiplier)
- Embedded NC107i ethernet
- 2X free Pci Express slots!!!
- 200W PSU (standard Flex format)
- Hp website ProLiant Microserver
- PDF specs and info
- Tour / photos of HP ProLiant Microserver
Links about 3rd party RAM for this box: 240-pin DIMM – DDR3 PC3-10600
- You can install Non-ECC RAM just fine (don’t mix and match ecc/non-ecc).
- You can upgrade a single stick at a time with different capacity on each stick
- CRUCIAL: ($35/$79 2G/4G stick)
- Kingston: $30/2Gig
- Kinston: $90/4Gig
- NewEgg (2Gb sticks): $30/ $27/$29
Other Chipset info:
The CPU family is certainly a major decision. But from there we have to review what chipset we will seek to build our system. Most of those components will come with the motherboard. Others will or can be obtained via a PCIe card.
We have selected the Atom processor family. We are only really interested in dual core processors, leaving us with the Atom 330, the more modern D510 or the latest D525. The common chipset found surrounding those Atom CPUs are listed below with some comments:
- NM10: 2xSATA – no port multiplier
- ION: 4xSATA – no port multiplier
- Jmicron623: 2xSATA (port multiplier)
- ICH9: 6x SATA, Partial port multiplier – support unclear)
Most (all?) Atom motherboards come with a very basic video capability (which is what we need). While they all have some SATA capabilities and ethernet connectivity, many motherboards have anemic specs (only 2 SATA, only 10/100Mb/s ethernet). Most Atom motherboard only have one and sometimes two PCIe 1x expansion slots and come in Mini-ITX or Mini-DTX form factor. Some of the inadequacies can be corrected with a PCIe card but plug-in cards increase the power consumption and there is only a limited of expansion slots.
Concerning the ethernet chipset, I find myself carrying a bias in favor of Intel which almost always is well supported on Linux and provides good performances.
This gives us a pretty good idea of what chipsets we are looking for when shopping for a motherboard. In a subsequent post, we review a number of motherboards for this project.
I now needed to evaluate available off the shelf components for the system. Since I wanted a nice, small, power sipper system, it seemed natural that I would want a system that can be expanded with external(s) disk units if/when the need arose instead of building another beast that can accommodate the maximum number of disks I could ever dream of! That brings us to the first and (I thought) the most unlikely component to find off the shelf: the external disk expansion unit.