External Hard Drives
Increasing capacity, increasing throughput
Simple to install and more affordable, an external hard drive is an interesting solution to extend the storage space of a computer. Whether mobile or destined to remain on a desktop, network accessible or not, or is not capable of playing media files ... To each to choose according to their needs.
A desktop hard drive is relatively bulky and can weigh over a kilo. These memory units are not really mobile products, even if they are transportable. Their storage capacity ranges from 750 GB to 8 terabytes (TB) 1 for prices ranging from 130 to more than € 600. Not to be confused with the "buffer" memory (or memory "cache"), 8, 16 or 32 MB, which serves to optimize performance (and does not constitute a selection criterion).
The size of the plates that make up serves as their generic name: it comes to hard drives 2.5-inch and 3.5 inch. The rotational speed of the 3.5-inch hard drives today reaches 7200 rpm (rotations per minute), which ensures a good flow of writing and reading data. This performance, however, obliges manufacturers to integrate a power supply, which forced to have an electrical outlet nearby.
Lighter (around 200 g), and thus more suitable to transport, portable external hard drives have, themselves, of 2.5-inch platters. They offer smaller capacities from 500 GB to 2 TB, for prices ranging from 50 to 200 €. Their trays currently running at a speed of 5400 rpm, providing de facto a slightly lower rate than "fixed" disks, but it avoids the mains connection during use: the connection to the computer, via USB or other sufficient.
There are also portable hard drives wi-fi, to extend the storage space of a smartphone or a touch pad . The wi-fi makes it possible to connect the hard drive to the smartphone or tablet, after which the user can copy its files in both directions, since an application downloaded from online stores App Store (Apple) or Google Play Store (Android). File transfer is however not as fast as a wired connection. Note that you can also play back files (music, for example) on your phone, wi-fi, without copying them.
A housing to save money
An alternative solution is to buy an internal hard drive and slide in a housing, bought parallel. There are both formats (2.5 and 3.5 inches). Performance is similar, but the cost for the use can be more interesting, especially for users, handling large data volumes, juggle multiple hard drives. It takes between 20 and 50 € for a housing and € 100 for an internal hard drive 3.5-inch 2TB. An equivalent external hard drive is priced around € 150.
The future is USB 3.0
The connection present on the hard drive is very important: it is from this that depends on the speed of data transfer to and from the computer. All models feature a USB 3.0 connector, which offers speeds (theoretical) 600 MB / s, 10 times faster than USB 2.0. Firewire and eSata ports, by contrast, are declining.
Quiet and airy
An external hard drive office, usually on permanently, should not make too much noise in operation. The hum of some models equipped with a cooling fan can become very annoying after a few hours.
In order to put the best external hard drive on the workspace, provided cables should be long enough. A meter appears to be a minimum for a connection with a computer under a desk. Manufacturers tend to generalize the brackets for placing hard drives vertically. On a desktop, the space savings is obvious, even if the tipping risk is greater. With or without a fan, the models 'bodywork' aluminum are generally more expensive, but provide better cooling of the hard drive. They are intended for prolonged and intensive use. For occasional use, a plastic casing enough.
Multimedia Hard Drive ...
One commercially-called hard disks "multimedia", which allow course to store files, but also know how to read. Simply transfer photos, videos, or its files MP3 to disk, and then connect it to the TV or the stereo for viewing (or listening). Common compression formats are generally supported (MP3 and AAC for music, DivX video, JPEG, BMP and sometimes PNG for images). One tip, if you have a flat screen: Make sure that the disc has an HDMI socket to enjoy high definition images. Moreover, the presence of an antenna on the housing indicates that the drive is compatible wi-fi: there you can drop files from your computer wirelessly.
... Or disk "network"
Finally, there are hard drives "network" (NAS, Network Access Storage), which can be shared between multiple computers by connecting to a router. Like any network element (computer, but also shared printer, for example), this type of hard disk has an IP (Internet Protocol). Multiple computers can access through an Ethernet connection, or wirelessly via a Wi-Fi network. A management interface typically used to configure its settings (access rights, etc.) from their computer. 500 GB to 2 TB capacities are variable and partly condition their price, between 100 and 600 €.
HDD to personal cloud
In recent years, hard drive manufacturers have stronger competition online storage solutions (Dropbox, Skydrive, etc.). The cloud is now democratized. To stay in the race, so some clouds offer "personal" (Western Digital My Cloud, Seagate Central). These hard drives of large capacity enough (2, 3, 4 TB) that connects to the Internet through the box of the home. One can store their documents, photos, films or music and view them remotely from a computer, a touch pad or smartphone. Everything is recorded at home, not on servers located enigmatic nowhere on the planet. The downside: saving files is your responsibility, and if you lose the disk (during a burglary, for example), you lose your data.