Page 2 - A Closer Look - Hardware (External)
The QNAP TS-251B's external design is similar to the TS-253B, albeit with a different color scheme. I found the white plastic cover, silver accents, and rounded corners to be quite attractive. My only complaint is this kind of plastic covers are epic fingerprint magnets; not to mention they scratch and swirl almost just by looking at it. Thankfully, it is white, so imperfections do not show up clearly. That aside, as the TS-251B is meant to be a home entertainment device, it is great to have something that looks good in the living room. Furthermore, in my personal opinion, it will not look out of place in an industrial setting either. That said, while the cover design is a departure from mainstream systems, there is nothing too radical at heart -- and this is a good thing. This is still a two-bay device in its traditional form factor. Measuring in at 10.5cm wide, 22.6cm deep, and 16.8cm tall according to specifications, these figures are very similar to comparable boxes in the range. Like many new network attached storage systems we have reviewed in the past, the QNAP TS-251B features an external power brick; we will cover that in detail in just a moment. The advantage of this is that a heat source is placed outside the system for improved thermal efficiency.
Even though the QNAP TS-251B features a white plastic cover, the NAS still features removable front-loaded drive trays like ASUSTOR's latest AS4002T and other devices based on the same chassis. In order to access the removable front-loaded drive trays, simply slide a tab lock down on the left, give it a quick tug, and the magnetic cover will pop right off. The tradeoff is the lack of ventilation slots on the front cover means cooling performance will be affected slightly. For the current design, airflow is over the hard drives driven by the rear mounted cooling fan inside the system and enters the NAS through ventilation slots at the bottom and on the side; more on this later.
QNAP's logo is printed on the top left corner of the plastic cover; whereas a silver surface occupies a slim vertical portion on the right. An array of LEDs under the power button indicates system status, LAN status, and USB status, respectively. The system status LED will turn off when the hard disks are on standby. Each independent hard drive has its own status LED as well. The drive status LEDs flashes when there is disk activity and remains on when it is idling. It turns red if the system determines the corresponding hard drive is in trouble. Extensive documentation on the behavior of the indicator LEDs can be found on the company's website. Below the array of LEDs is a USB 3.0 Type-A port and a one-touch copy button. Unfortunately, there is no front panel display, but it is excusable since this a budget product. With its excellent design, there is absolutely no learning curve for users who are familiar with using QNAP NAS systems -- it is all plug and play.
The QNAP TS-251B is constructed on a steel frame, while its shell that covers the remainder of the sides of the system is composed of white plastic. The textured plastic is reasonably resistant to fingerprints and scratches. What we have at the back of the system is simple but generous configuration of connectors. Here, we have one USB 3.0 port, three USB 2.0 ports, one HDMI 1.4b connector, one Gigabit Ethernet port, two 3.5mm dynamic microphone inputs, one 3.5mm speaker line out jack, and a DC 12V input from the external power brick. There is also a Kensington lock near the bottom. Occupying a large chunk of space at the back is a single 70mm exhaust fan to pull heat out of your NAS server. Exhaust vents are cut into the steel panel. In my opinion, a proper fan grille would have been better, but this should not affect cooling performance to a significant degree.
The plastic shell is attached by two screws. You will not void your warranty if you want to open it up, because you will have to do so in order to upgrade the RAM. Hard drive installation does not require you to take the plastic shell off. What the warranty seal covers is a screw that attaches the motherboard to the chassis frame. You will void the warranty only if you want to take the motherboard out, which is not something a typical person will do. There are no other user serviceable parts inside. Therefore, I think the warranty seal is placed in a reasonable location. We will dig into the TS-251B's interior in more detail on the next page.
There is nothing particularly exciting at the bottom of the QNAP TS-251B's chassis; what you will see here are four small legs affixed on top of its plastic shell. As always, they are installed to reduce vibration noise, increase grip, and prevent surface scratching. The bottom of the network attached storage system features a neat matrix of ventilation openings. It is placed right near the front, below the hard drives bays inside, as an air intake. A small inscription at the bottom indicating locked and unlocked is present to indicate the position of the plastic shell. You know, in case you could not tell it was open or closed in the first place.
1. Introduction, Packaging, Specifications
2. A Closer Look - Hardware (External)
3. A Closer Look - Hardware (Internal)
4. Configuration and User Interface, Part I
5. Configuration and User Interface, Part II
6. Configuration and User Interface, Part III
7. Performance and Power Consumption