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.
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.
