Comparison Synology DiskStation DS725+ vs Synology DiskStation DS225+

Number of M.2 slots provided in the design of the NAS server.

M.2 slot is used for connecting various internal peripheral devices, mainly of a miniature form factor. This solution allows reducing the size of the NAS server itself. Solutions without 2.5" and 3.5" slots can make it compact. It is worth noting that this slot can implement two electrical (logical) interfaces — SATA 3.0 and PCI-Express, with each individual M.2 socket on the board being able to support either both interfaces simultaneously or just one of them. These details should be clarified before purchase, as they directly affect the capabilities of using M.2. For instance, with SATA 3.0 support, such a slot has a significantly lower speed compared to PCI-E; therefore, this M.2 variant is mainly used for inexpensive SSD modules. In turn, PCI-E is somewhat more expensive but provides maximum data transfer speed and allows connecting high-class solid-state drives to the NAS server.

Number of ports USB 3.2 gen1 provided in the design of the NAS server.

USB connectors are used in computer technology for connecting various external peripherals. In the case of NAS servers, this usually refers to external storage devices — flash drives, hard drives, etc. This allows information to be transferred from the internal storage to an external one (for example, for backup purposes) or vice versa, and even to expand the overall working capacity of the server. Additionally, in models with a VGA output (see below), a keyboard can also be connected via USB, and in models with a print server function (see "Software Features"), a printer can be connected accordingly. For added convenience, the USB connector can be placed on the front panel (see below).

Specifically, USB 5Gbps (previously known as USB 3.0 and USB 3.2 gen1) is the direct successor of USB 2.0 and the most widespread USB standard today. This version provides a data transfer speed of up to 4.8 Gbps, as well as fairly high power supply. These connectors are backward compatible with peripherals using USB 2.0.

A modern universal connector for connecting external drives, flash drives, docking stations, or other compatible devices. It may not be limited to a single USB-C port and also provides for different versions that affect data transfer speed.

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.

The number of cores provided in the processor of the NAS server.

Initially, each core is a computing module designed to execute one sequence of instructions. Accordingly, multiple cores make it possible to work simultaneously with multiple data streams, which improves flow Rate - especially when processing multiple tasks at the same time. Also, in modern CPUs, multithreading technologies are increasingly being used, which allow loading each core with two sequences of commands at once. During the inevitable pauses in the execution of one of the threads, the kernel does not idle, but works with another sequence. As a result, the total number of threads in such processors is twice the number of cores; this scheme of work even more noticeably improves flow Rate.

It is also worth remembering that the overall capabilities of the processor are highly dependent on a number of other characteristics - microarchitecture, clock speed, support for special functions, etc. This means that a large number of cores does not in itself guarantee high flow Rate: for example, an inexpensive mobile processor on 4 cores may well be "weaker" than an advanced desktop chip with only 2 cores. However, if we are talking about a CPU with a similar specialization and clock speed, then a solution with a large number of cores ( 6 cores, 8 cores, or ev...en more) and multithreading support usually turns out to be more productive.

Clock speed of the processor installed in the NAS server.

The clock frequency is the frequency of the built-in oscillator, according to which all operations performed by the processor are synchronized. The higher this frequency, the more operations per second the CPU can perform and the easier it is to provide high computing power in it. However, note that the actual speed of the processor depends on many other features — the number of cores (see above), microarchitecture, volumes of the built-in cache memory, etc. So, only chips with similar characteristics and purpose can be directly compared by clock frequency ( desktop/mobile) and price category.

Processor clock speed achieved in TurboBoost or TurboCore "overclocking" mode.

Turbo Boost and Turbo Core technologies are used by different manufacturers (Intel and AMD, respectively), but they have the same principle of operation: load distribution from more loaded processor cores to less loaded ones to improve performance. The "overclocking" mode is characterized by an increased clock frequency, and it is indicated in this case.

For more information about clock speed in general, see the relevant paragraph above.

The amount of RAM on the NAS server. Along with the processor, it is one of the indicators that determine the speed of the system — the more memory, the higher the computing power. However, in fact, it does not always make sense to chase large amounts of "RAM", which can reach 4 GB, 8 GB and even higher; see "Processor" for details.

The maximum amount of RAM that can be installed on the NAS server. It depends, in particular, on the type of memory modules used, as well as on the number of slots for them.