External and internal hard drive for laptop

In recent years, the problem of choosing a convenient storage device is becoming more urgent. Famous compact discs, first appeared in 1982, went through a long and glorious path of development. Initially, on such a disk it was possible to store 700 MB of data (the first models with 650 MB quickly evolved). With the increase in the volume of software distributions, more capacious disks were needed - so the DVD appeared. Currently, the most popular technology is Blu-Ray with its 25 GB and more capacity. But more and more often the opinion is voiced that the development of CD-ROMs for backup and storage tasks will be completed, giving way to solid-state media. This is not always obvious, but the progress in this area is especially closely watched by laptop owners. To replace the CD-ROM drive or to install inside the system unit of the personal computer an additional hard disk does not present any complexity. But in laptops, everything is not so simple. The second hard disk can not be put on the laptop by the usual way, because the components inside the case are very tight and there is no free space.

However, with the development of the USB bus appeared quite a lot of devices, including an external hard drive for a laptop. Unlike the usual varieties for internal installation, such hard disks (HDD) have a USB interface that supports hot-plug / unlock devices (which was not, for example, on the IDE). The hard disk for the laptop is connected very simply: just a USB cable coming from the HDD is included in any free corresponding port on the laptop. As a result, the operating system will determine the connection status and, if the disk already has a file system, automatically assign a letter, allowing you to work with the device. When selecting an external USB drive, it is recommended that you pay attention to the way you organize your meals. Some models use a USB bus for communication with a laptop, but for power supply - a small external unit, which is less convenient. Others do not require such a unit, being content with 500 mA from the port (or 1 A, in case of using Y-Cable). Nevertheless, it should be noted that models with a power supply often have higher speed and capacity. External HDD is most often used as a backup storage of important data or a portable device (remembering CDs).

Hard disk for laptop and computer (PC) are selected in different ways. If for PC the main criterion is productivity and capacity, then for portable models energy efficiency is added to the list. After all, a mobile computer should run on battery for a long time, which is why a hard disk for a laptop almost never comes with 10,000 spindle revolutions. Such a solution would be very wasteful in terms of battery power consumption.

Buying an internal hard disk for a laptop, you need to determine the type of interface. At the moment there are two of them: IDE and SATA. They are not compatible with each other, so the HDD interface and the controller on the motherboard must match.

The spindle speed (RPM) determines the performance, heating and power consumption. The fastest models are from 7200 revolutions, the compromise version is 5400, and the slowest ones (are encountered less frequently) are 4200. The higher the rotation speed, the more heating and energy costs.

One of the characteristics of a hard disk is the amount of cache. The more it is, the better.

Currently, there are hard drives based on solid-state flash memory. They do not have moving mechanical parts, have low energy consumption, weigh little, and speed characteristics are approaching (and even ahead of) analogs with magnetic disks inside. One of the disadvantages is the high cost.