Form factor
The form factor in which the hard drive is made.
This indicator determines primarily the size of the device. But its more specific meaning depends on the execution (see the relevant paragraph). So, in the case of external drives, only the overall dimensions of the case depend on the form factor, and then quite approximately. But internal HDDs are installed in slots with a well-defined size and location of holes for fasteners; these holes are made specifically for one form factor or another. For desktop PCs, the standard form factor is
3.5", for laptops —
2.5" ; at the same time, there has been a recent trend in desktops towards miniaturization and the transition to 2.5-inch drives. Theoretically, there is an even smaller form factor — 1.8", but in fact it is used mainly among ultra-compact external HDDs.
Connection
— SATA. Nowadays, it is the most popular interface for connecting internal hard drives.
the first version of SATA provides a data transfer speed of about 1.2 Gbit/s,
SATA 2 has a practical data transfer speed of about 2.4 Gbit/s (300 MB/s), and the most advanced generation
of SATA 3 has a speed of 4.8 Gbit/s (600 MB/s)
- eSATA. Modification of the SATA interface designed for connecting external hard drives; not compatible with internal SATA. Practical data transfer speed is similar to SATA 2 and is about 2.4 Gbps (300 MB/s).
- SAS. Modification of the SCSI interface provides data transfer speeds up to 6 Gbit/s (750 Mb/s). It is used mainly in servers; it is practically never used in desktop PCs and laptops.
-
USB 2.0. The earliest of the USB standards found in modern hard drives - and exclusively external ones (see “Execution”). Provides connection to a traditional full-size USB port, provides data transfer speeds of up to 480 Mbit/s, as well as fairly low power supply, which is why drives with this type of connection often require additional power. In light of all this, as well as the emergence of the more advanced USB 3.2 standard (see below), today USB 2.0 is considered obsolete and is extremely rare, mainly in inexpensive and early models of drives. However, a disk with this interface can also be connected to a n
...ewer USB port - the main thing is that the connectors match.
— USB 3.2 gen1(previous names USB 3.1 gen1 and USB 3.0). A standard for connecting external HDDs, which replaced the USB 2.0 described above. Uses a traditional full-size USB connector, provides data transfer speeds of up to 4.8 Gbps (600 MB/s), as well as higher power supply, making it easier to do without external power in such drives. However, for the same reason, you need to be careful when connecting USB 3.2 gen1 drives to older USB 2.0 connectors - such a connector may not have enough power to power a newer drive.
- USB 3.2 gen2. Further development of the USB 3.2 standard (previously known as USB 3.1 gen2 and USB 3.1). The maximum data transfer rate in this version has been increased to 10 Gbps, and the power supply can reach 100 W (with support for USB Power Delivery technology). At the same time, drives with this type of connection can also work with earlier versions of full-size USB connectors - the main thing is that there is enough power supply.
— USB C 3.2 gen1(previous names USB C 3.1 gen1 and USB C 3.0). Connection via USB C connector, corresponding to USB 3.2 gen1 capabilities. These capabilities are described in more detail above; the difference from the “regular” USB 3.2 gen1 in this case lies only in the type of connector: it is a relatively small (slightly larger than microUSB) socket, which also has a double-sided design. Thanks to its compact size, USB C is found both in full-size PCs and laptops, as well as in compact gadgets like smartphones and tablets; Some drives with this connection initially allow “mobile” use.
— USB C 3.2 gen2(previous names USB C 3.1 gen2 and USB C 3.1). Update and improvement of the USB C 3.2 gen1 described above - the same USB C connector and increased data transfer speed to 10 Gbps (as in the “regular” USB 3.2 gen2).
- Thunderbolt. High-speed interface for connecting external peripherals. It is used mainly in Apple computers and laptops, although it is also found in equipment from other manufacturers. Note that in modern HDDs there are mainly two versions of Thunderbolt, which differ not only in operating speed, but also in connector: Thunderbolt v2(up to 20 Gbps) uses a miniDisplayPort plug, and Thunderbolt v3(up to 40 Gbps) — USB C plug (see above). In light of this, some hard drives implement USB C and Thunderbolt connections through a single hardware connector, which automatically detects which computer input the device is connected to.Manufacturer's warranty
Manufacturer's warranty provided for this model.
In fact, this is the minimum service life promised by the manufacturer, subject to the rules of operation. Most often, the actual service life of the device is much longer than the guaranteed one.
RPM
For drives used in a PC (see "Intended use"),
5400 rpm(normal) and
7200 rpm(high) are considered standard speeds. There are also
more specific options, including models with the ability to adjust the speed depending on the load. In server HDDs, in turn, higher speeds can be used —
10,000 rpm and even
15,000 rpm.
Power source (external)
—
USB port. Powering an external hard drive directly through the USB connector used to connect to a computer. The advantage of such disks is that they do not require a separate power supply — thus, they can be used even with laptops in the absence of an electrical outlet. However, it is worth considering that the power of the current supplied through the USB connector may sometimes not be enough to start the disc — especially if the connection is made through a USB hub at the same time as several other devices.
— Thunderbolt. Powered directly through the Thunderbolt connector — the same one used for the main connection. For more information about the connector itself, see “Connection Interfaces”, otherwise this option is completely similar to the USB power supply described above (adjusted for the fact that Thunderbolt does not use hubs).
—
Power supply. Power supply of an external drive from a separate unit connected to a standard 220V network. Such drives may have a connection interface other than USB, are free from problems associated with insufficient power supply, but their mobility is limited by the availability of electrical outlets.
