M.2 connector
The number of M.2 connectors provided in the design of the NAS server.
The M.2 connector is used to connect various internal peripherals, mostly miniature form factor. Note that two electrical (logical) interfaces can be implemented through this connector — SATA 3.0 and PCI-Express, and each individual M.2 socket on the board can support both of these interfaces at once, or only one of them. These nuances should be clarified before buying, since the possibilities for using M.2 directly depend on them. So, with support for SATA 3.0, such a connector is intended exclusively for drives, and the speed of SATA is noticeably lower than that of PCI-E; so this M.2 variant is mostly used by inexpensive SSD modules. In turn, PCI-E is somewhat more expensive, but it is faster and more versatile. Support for this interface allows you to connect both high-end SSDs and various expansion cards (for example, sound cards or internal wireless adapters) to the NAS server.
PCI-E
The number of
PCI-E slots provided in the design of the NAS server.
PCI-E is one of the most popular modern interfaces for connecting internal components to a computer motherboard. Specifically, in NAS servers, it can be used, in particular, for wireless adapters and SSD drives; in the latter case, PCI-E allows higher speeds than SATA and fully realizes the potential of solid-state memory. And the number of such connectors corresponds to the number of PCI-E components that can be simultaneously installed in the server.
Note that the PCI-E connection can use a different number of lines (1x, 4x, 16x), and for normal operation it is necessary that the slot on the "motherboard" has no fewer lines than the installed component. In fact, this means that a component with a 1x connector will easily fit into any slot, but with a larger connector, the connection should be specified separately. However, in the case of NAS servers, even PCI-E 4x capabilities are rarely required, not to mention 16x.
USB 2.0
The number of
USB 2.0 ports provided in the design of the NAS server.
USB connectors are used in computer technology to connect various external peripherals. In the case of NAS servers, we are most often talking about external drives — flash drives, hard drives, etc. In this way, you can transfer information from an internal drive to an external one (for example, for backup purposes) or vice versa, and even expand the total working volume of the server . In addition, on models with a VGA output (see below), a keyboard can also be connected to USB, and on models with a print server function (see "Software Features"), respectively, a printer. For added convenience, the USB connector can be placed on the front panel (see below).
As for USB 2.0 specifically, today this version is generally considered obsolete due to the relatively low speed (up to 480 Mbps) and the low power supplied through the connector. Peripherals of newer versions can be connected to such a port, however, the speed will be limited by the capabilities of version 2.0, and the power supply may not be sufficient. Therefore, in modern NAS servers, such connectors are quite rare — mainly as an addition to the newer and faster USB 3.2 gen1 (see below), designed for relatively unpretentious peripherals like keyboards.
HDMI
The presence of an
HDMI output in the NAS server; either the presence of such a connector itself or its specific version can be indicated here.
HDMI is a digital interface specifically designed to carry high-definition video and multi-channel audio. This is the most common of these interfaces, most modern monitors, TVs, home theaters, projectors, etc. have this type of input. Thus, even in such a specific technique as NAS servers, such outputs have several applications. The first option is to connect a monitor to monitor the parameters of the server; some devices at the same time allow you to connect keyboards / mice and control the server directly, like a regular computer. The second option is to use the NAS server as a media centre to broadcast movies and other content to a TV, home theater, etc.
The specific functionality of HDMI should be specified separately. As for the versions, the following options are relevant today:
— v 1.4. Relatively old (2009), but still quite widely used version. Supports resolutions up to 4096x2160 (at 24 fps), as well as frame rates up to 120 Hz, which allows you to play 3D content as well. It is found both in the original version and in improved versions v 1.4a and v 1.4b — they have advanced features for working with 3D.
-v 2.0. Version released in 2013. The increased bandwidth compared to its predecessor made it possible to provide full support for 4K video (at frame
...rates up to 60 Hz), as well as multi-channel audio up to 32 channels and 4 streams over a single cable. HDMI v 2.0 did not originally support HDR, however this feature was introduced in the v 2.0a update and was improved and expanded in v 2.0b. With all this, old cables, originally designed for version 1.4, are also suitable for connecting according to this standard.
— v 2.1. Standard introduced in 2017. Also known as HDMI Ultra High Speed, bandwidth has increased so much that it is possible to transmit video at resolutions up to 10K at 120 frames per second. Note that to use all the features of this version, you need cables that were originally created for it (although the functionality of earlier versions will be available when connected via a regular cable).
In conclusion, we note that different versions of HDMI are mutually compatible, however, the signal transmission capabilities in such cases will be limited by the characteristics of the older and slower standard.CPU
The model and specifications of the processor installed in the NAS server. The speed of the device largely depends on these characteristics, primarily the clock frequency. However, in fact, this parameter is often more of a reference value: simple everyday tasks (say, FTP and print servers, see "Software Features") do not require high computing power. But for working with extensive databases (see ibid.), a “faster” processor may be useful.
Power consumption
The amount of power consumed by the NAS server during normal operation. Most often, we are talking about maximum power consumption — with all the occupied slots for drives, under high load.
Modern NAS, even high-performance ones, have rather modest power consumption — even among professional models with 10 or more drives, this figure rarely exceeds 1 kW. So there are no problems with connecting to a 230 V network. However, energy consumption information can be useful for some special applications, primarily for estimating the load on UPSs, emergency generators, stabilizers, and other special equipment.
Cooling
The type of cooling used in the NAS server.
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Active. Active cooling systems work on the principle of a heat pump — they forcibly remove heat from heating parts. In computer technology, including NAS, this function is usually performed by coolers — combinations of fans and heatsinks. Active cooling requires its own power, takes up a relatively large amount of space, and increases overall power consumption; in addition, it creates additional noise during operation, and it affects the cost. However, all these shortcomings are compensated by high efficiency: systems of this type can be used even in professional high-performance servers. As a result, they have become widespread.
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Passive. Cooling based on the natural removal of heat from heating elements; in other words, such systems do not take heat forcibly, but only facilitate cooling. The most common type of passive cooling in computer technology is a radiator — a ribbed metal plate; its action is based on increasing the area of contact with air. Sometimes radiators can be supplemented with so-called heat pipes that work by evaporating and condensing liquids. All types of passive cooling have simplicity, low cost and almost complete absence of noise during operation. At the same time, their efficiency is very low, and it makes sense to use such systems only in relatively simple low-power NAS servers.