The connection connector(s) used in the drive. Note that for outdoor models (see "Type"), here, usually, the connector on the case of the drive itself is indicated; the ability to connect to a particular jack on a PC (or other device) depends mainly on the availability of appropriate cables. The exception is models with a non-removable wire — they are talking about a plug on such a wire.
Some form factors — for example, M.2 — use their own standard connector, so this parameter is not specified for such models. In other cases, the connectors can be conditionally divided into external and internal — depending on the type of drives (see above). In internal modules, in addition to the same M.2, you can find
SATA 3,
U.2 and
SAS interfaces. External devices mainly use different types of USB — the classic USB connector (versions
3.2 gen1 or
3.2 gen2) or USB-C (versions
3.2 gen1,
3.2 gen2,
3.2 gen2x2 or
USB4). In addition, there are solutions with the Thunderbolt interface (usually versions
v4 or
v3). Let's take a closer look at these options:
— SATA 3. The third version of the SATA interface, providing da
...ta transfer rates up to 5.9 Gbps (about 600 MB / s). By SSD standards, this speed is low, since SATA was originally developed for hard drives and was not intended to be used with high-speed solid-state memory. Therefore, such a connection can be found mainly in low-cost and outdated internal drives.
— SAS. A standard designed as a high performance connection for server systems. Despite the emergence of more advanced interfaces, it is still found nowadays. Provides data transfer rates up to 22.5 Gbps (2.8 GB/s), depending on version.
— U.2. A connector specially designed for high-end internal drives in the 2.5 "form factor, mainly for server purposes. Actually, U.2 is the name of a specialized form factor (2.5", height 15 mm), and the connector is formally called SFF- 8639. Such modules are connected in the same way as PCI-E expansion cards (via the same bus), but they are smaller in size and can be hot-swapped.
— U.3. A three-interface connector based on the U.2 specification (see the relevant paragraph) and using the same SFF-8639 connector. The U.3 connector combines SAS, SATA and NVMe interfaces in one controller, allowing you to connect different types of drives through the same slot. U.3 provides separate pins for identifying a particular type of drive. The specification was created for internal 2.5" form factor drives. Such modules are miniature, hot-swappable, and support external control pulses.
— USB 3.2 gen1. Traditional full-size USB connector, compliant with version 3.2 gen1. This version (formerly known as 3.1 gen1 or 3.0) provides data rates up to 4.8 Gbps. It is compatible with other USB standards, except that the connection speed will be limited by the slowest version.
— USB 3.2 gen2. A traditional full size USB connector, corresponding to version 3.2 gen2 (previously known as 3.1 gen2 or simply 3.1). Operates at speeds up to 10 Gbps, otherwise the key features are similar to those described above USB 3.2 gen1
— USB-C 3.2 gen1. USB-C connector supporting 3.2 gen1. Recall that this version allows you to achieve speeds up to 4.8 Gbps. And USB-C is a relatively new type of USB connector, having a small size (slightly larger than microUSB), a symmetrical oval shape and a double-sided design. It is especially useful for external SSDs, given that such drives are getting smaller and smaller.
— USB-C 3.2 gen2. USB-C connector supporting version 3.2 gen2 connectivity — with data transfer rates up to 10 Gbps. However, such a drive will be able to work with slower USB ports — unless the speed will be limited by the capabilities of such a port. See above for details on the USB-C connector itself.
— USB-C 3.2 gen2x2. USB-C type connector supporting connection version 3.2 gen2x2. For more information about the connector itself, see above; and version 3.2 gen 2x2 (previously known as USB 3.2) allows to achieve speeds up to 20 Gbps — that is, twice as high as in the original 3.2 gen 2, hence the name. It is also worth noting that this version is implemented only through USB-C connectors and is not used in ports of earlier standards.
— USB4. A high-speed revision of the USB interface that uses only symmetrical USB type C connectors. Allows you to achieve data transfer rates of up to 40 Gbps (depending on the technologies and standards implemented in a particular port). The interface can support Thunderbolt v3 and v4, and is backward compatible with previous USB specifications, although devices with a full-size USB-A plug will require an adapter.The highest speed in write mode characterizes the speed with which the module can receive information from a connected computer (or other external device). This speed is limited both by the connection interface (see "Connector"), and by the characteristics of the device of the SSD itself.
The highest data exchange rate with a computer (or other external device) that the drive can provide in read mode; in other words —
the highest speed of information output from the drive to an external device. This speed is limited both by the connection interface (see "Connector"), and by the characteristics of the device of the SSD itself. Its values can vary from 100 – 500 MB / s in the slowest models to 3 Gb / s and higher in the most advanced ones.