Insider Details: QNAP TS-470 Turbo NAS
Before we dig into the real innards of the QNAP TS-470, here’s the “drives eye” view of the NAS. Twelve pins worth of power enter from the upper left, and it’s easy to see the traces that angle down towards the power portion of the SATA connectors. The signal portion of the SATA interfaces are located right below them, and although the backplane looks like it’s just a passive connector board, there is a Marvell SATA controller chip located on the upper left, just out of sight behind some sheet metal. The main cooling fan is partially visible from here, and the fins from the CPU cooler are too, although they’re tougher to see when viewed on edge.
The top cover is easily removed once three small screws on the back panel are removed. The modular layout is quite evident; the main board takes up the whole left side of the unit, and the PSU is sitting right on top of the drive bay. The cooling fan is mounted on the rear panel, right in line with the drive bay. The CPU back plate dominates the back surface of the controller board, evidence that this is no Atom-based device, and that there is more power on tap than usual. The QNAP TS-470 Turbo NAS server is equipped with an Intel Celeron G550 processor, which is based on the 32nm Sandy Bridge architecture, and is clocked to 2.6 GHz, according to QNAP. The TS-470 doesn’t have the top-of-the-line CPU in QNAP NAS servers – that would be the systems with Xeon processors, but a modern dual-core Celeron is still a huge step up from any Atom-based model. The only question is whether it has enough horsepower to max out the system performance in a four-bay unit, and we’ll find that out shortly. That long, dense row of pins above the CPU is the 16x PCIe 2.0 expansion slot, which makes all the difference in terms of performance flexibility. On the lower right of the controller is where the DRAM modules are located, and you can see that the SO-DIMM slots do not face this direction, they are pointed towards the internal drive bay. This makes it very difficult to upgrade the DRAM, and QNAP does not officially support any memory upgrades for the TS-x70 units, anyway.
Looking straight down from the top, you can see the installed expansion card better, as well as the power supply wiring to the main board and the backplane. The wiring from the PSU to the main PCB is very straightforward and short. The main controller board has a familiar ATX arrangement, and the backplane PCB gets its own dedicated power connector direct from the PSU, for all those power-hungry HDDs. If you think about how much current it takes to spin up large capacity drives, with three or four heavy platters inside each one of them, it’s clearly a good idea to have substantial power cables feeding the backplane PCB directly. The blue expansion card is a dual port NIC, with a 4x PCIe 2.0 interface. The expansion slot uses a 16x connector and is wired for all 16 lanes, but the two GbE ports only need 4x to get by. I’ll be doing a portion of the testing for this model with the QNAP LAN-10G2T-U, Dual-port 10 Gigabit Network Expansion Card, which has two 10GBASE-T ports, with standard RJ-45 connectors. The firmware instantly recognized the 10GbE NIC and there was no manual configuration required to get it up and running. Several models from Intel and Emulex are also supported, with options for fiber optic cabling and SFP+ ports, too. I’ve personally tested the Intel X520-T2 (E10G42BT) adapter on a similar QNAP Turbo NAS and also had a solid, carefree experience with that combo.
Once the rear panel is removed, if you look back inside the TS-470 chassis, the secret CPU cooler is revealed. Power has a price, and in the case of CPUs, part of that price is excess heat, that must be dissipated out of the electronic package and into the atmosphere. Fitting this miniature heat pipe style cooler in here was probably a bit of a challenge for the packaging engineers. It did make disassembly of the NAS unit a little more difficult, but otherwise it fits in like it was always there, from the beginning. One other thing that’s clear to me is that there’s room left for expansion, if a more powerful CPU is needed. All that’s needed is to make the heat pipes a little longer and add more fins towards the left. The Intel G550 does everything this 4-bay NAS needs, but the TS-870 might benefit from an i3 or i5 solution.
If you could crawl inside the drive bay, and had X-ray vision, this is the view you would get of the main controller board for the QNAP TS-470. Typical for SFF computing, the CPU cooling solution dominates the physical landscape. Although all the elements of a mini-ITX board are present here, the overall layout and feature set don’t match up. In the rack mount NAS units, there’s a bit more flexibility in packaging, and more standard designs can be used. A case in point on this board is the small 4x PCIe connector towards the bottom, that’s mounted 90 degrees out of phase from the 16x expansion slot at the top. The small 4x connector is for the SATA backplane, which you won’t find on a typical mini-ITX PC.
Speaking of the SATA backplane, here it is, in its entirety. The edge connector transfers the PCIe signals to this vertical board that serves as the backplane for all the SATA HDD connectors. It’s not just a passive board, as there is a drive controller IC located on the backplane. This is consistent with how QNAP builds their larger tower models, putting the controllers closer to the drives they are responsible for. The Marvell 88SE9235 SATA controller chip handles all four drives, so the board isn’t littered with active ICs, but it’s easy enough to spot. All the other larger components mounted on the board are power supply and monitoring chips.
The memory controller is integrated on the Intel G550 Celeron CPU, and it’s designed to handle DDR3-1066 memory modules in its native configuration. The QNAP TS-470 comes standard with 2GB of DRAM, which is installed in one of the two SO-DIMM sockets located on the main board. The specs for the TS-470 don’t call out a maximum memory capacity more than the 2GB that’s already installed, but it’s more than adequate for a NAS running Linux. Similar models have been running OK on 512MB for several years. Based on my testing, straight data transfers use very little of the NAS memory capacity. There are dozens of more challenging apps that you can run on a QNAP NAS though, and the extra memory might have a bigger impact on some of those. Installing additional memory would surely invalidate the warranty, since the only way to get the SO-DIMM into the second socket is to take the NAS almost completely apart. Based on QNAP forum postings, this does not bother everyone…..
So far we’ve had a good look at what there is to observe as far as hardware goes, but let’s dig down one more layer, down to the chip level where the technology really starts to get interesting. I love my hardware just as much as the next person, but it’s only half the story….