External hard drive is the ultimate solution when you are looking for backup solutions for your computers. However, it has become increasingly difficult with the numerous types and options. Before you buy an external hard drive, it is important that you know which type is the best for you, and it definitely requires a bit of research. We have simplified the task for you by having it all in here. External Hard Drives can be broadly classified based on four different attributes: Portability, Interface Connectivity, Usability and the Operating System.
External Hard Drives classification based on Portability
Desktop External Hard Drives (2.5″ Hard Drives):
The external desktop hard drives are mainly the highest capacity drives in the market. They are usually about the size of a book. They come in capacities of up to 6TB. Because of their big size, they are not portable, and are parked on the desk. Being big and bulky also means that they are power hungry, and are not one of those plug and play types; they mostly depend on external power sources. Desktop External Hard Drives are high on functionality and features. However, being big in size does not mean that it is the fastest, the external desktop hard drive is on the slower side.
Portable External Hard Drives (3.5″ Hard Drives):
Portable external hard drives are the popular ones on the block, with sizes of about a deck of cards. These portable hard drives, as the name indicates, are “portable”. With limited size, the capacities are also smaller. As of 2011, the popular capacities in this category are, 250GB, 350GB, 500GB and 750GB. The portable hard drives have heaps of advantages, and one of them is that, it is small enough to get powered via its USB port, and often does not need any external power; just plug and play. Though they might not be feature packed, they are on the faster side of things. The portable hard drives are also much fancier than the desktop hard drives.
External Hard Drives classification based on Connectivity
Most of the external hard drives have any one of the following interfaces: USB2.0, USB3.0, FireWire and eSATA. Your choices might be limited to the type of ports that you have in your system, but if you do have a range of ports available, then you do get to choose the best one for you.
USB (Universal Serial Bus) was developed during the 1990s, and was mainly designed to standardise the connection of peripherals, both for the sake of communication as well as to supply power. USB was the interface that effectively replaced the earlier interfaces such as the serial and parallel ports. It also replaced the need of separate power chargers for portable devices. The interface is so popular, that over 10 billion USB device have been sold till date. Though there were various versions of USB released, such as, USB 0.7, USB 0.8, USB 0.9, USB 0.99, USB 1.0, USB 2.0 and USB 3.0, only the latter three are in use for now.
USB 2.0 is one of the most common interfaces offered in most of the external hard drives, and one of the most easy to use too. The USB 2.0 was released in April 2000, and adds a higher maximum bandwidth of 480 mbps, which is also called “Hi-Speed”. USB2.0 has been available for so many years that it would not be an exaggeration if we said that each and every computer, including desktop PCs, laptops, netbooks and servers in both the worlds of Windows and Mac.
However, the Hi-Speed, which was then considered as an advantage, is now quite a disadvantage, because, the 480mbps is quite limited, translating to just 30 – 35 mbps maximum bandwidth for most of the typical storage applications. Even though this seems to be more than enough for most of device types for the some casual storage, but as the capacity of the external hard drive increases, on a regular basis, you will crave for more throughput.
To eliminate this disadvantage of limited bandwidth, USB 3.0 was developed and announced on 17th November 2008. USB3.0 has transmission speeds of up to 5gbps, which is about ten times faster than the original USB2.0. This technology significantly reduces the time that is required for data transmission. In addition to this, it reduces power consumption, and is even downward compatible with USB2.0.
Some of the best USB3.0 compatible drives take full advantage of the amazing speed of this technology. However, some of the cheaper USB3.0 are not so fast, and for now, USB 3.0 is only available in very few PCs. That said, USB3.0 is the fastest interface of all, and hence the external hard drives with this interface tops the list of speedy drives.
eSata is an external variant for SATA and is basically meant for external connectivity. eSata is mainly aimed at the consumer market, and hence was introduced to the market of external hard drives, which was then served by the FireWire and USB interfaces. The External Serial Advanced Technology Attachment is much faster than the USB2.0 interface, and that is by a lot. Yes, a lot, as it is about four times faster at 157Mbps. Even though USB3.0 has a much faster theoretical transfer speed, of 4.8gbps, experts have reported that eSATA will work much better in real life.
However, the major issue is that, eSATA is not as universal as its rival USB2.0. Hence, most of the computers do not have the eSATA port, stopping most people from buying eSata based external hard drives.
FireWire, which is also known as IEEE 1394 is an interface that has been around for a long while. FireWire is actually Apple’s name for this High Speed Bus. Apple initiated it and was developed by IEEE P1394 Working Group. This research and development was largely driven by Apple, however most contributions were made by the engineers from Texas Instruments, IBM, Digital Equipment Corporation, Sony and STMicroelectronics. There are two major versions of FireWire that were employed in external hard drives; FireWire 400 and FireWire 800.
With the FireWire 400, you will be able to get 400mbps throughput along with isochronous transfer. This helps with real time data transmission for digital video. The next version, FireWire 800 has twice the throughput at 800mbps. However, none of these two versions became mainstream. Though the interface is widespread, it is not even close to the popularity of USB. Some of the future FireWire standards such as 1394d, can reach up to 6.4gbps, but there are chances that they are not mainstream either. A final nail on FireWire’s coffin was that, Apple has recently ditched FireWire from its consumer line in favour of USB.
External Hard Drives classification based on Usability
The rugged external hard drives are especially for the adventurous lot. The rugged external hard drives usually come with rubberised covers and up to the standards of “ruggedness”. The rugged drives protect all your data on bumps, knocks, drops, waterproof and shock resistant too. Some of the popular rugged external hard drives include LaCie Rugged All-Terrain External Hard Drive, ADATA External USB Hard Drive, Iomega eGo Portable Compact USB3.0 EHD, Freecom 30570 ToughDrive 2.5” EHD and Transcend StoreJet Mobile 2.5” USB2.0 Portable hard drive.
Multimedia hard drives are relatively a new generation of external hard drives. They are set to bring in the amazing diversity of multimedia that was once confined just to your PC. With multimedia hard drives, they can enjoy the more comfortable surroundings of your living room. The multimedia drives backup all your media from your system, and can then be played by connecting to your TV or HDTV directly, and enjoy all your movies, music and images with family and friends.
Multimedia drives can be classified into two main categories of pocket multimedia drives that sport 2.5” hdd and desktop multimedia drives that are based on 3.5” hdd.
Some of the popular multimedia external hard drives include WD Digital HD Network Media Player, Iomega 1TB Multimedia hard drive, Buffalo LS-WX1.0TL R1 Multimedia Network Storage, LaCie 301865EK multimedia HDD and heaps more.
Network Hard Drives:
Network hard drives, as the name indicates, will back-up a network of computers. Obviously, all of the network hard drives have an Ethernet port to keep the computers in the network connected. The Network External Hard Drives usually come in higher capacities such as 1TB and 2TB. They also come with Cloud, that allows you to securely share your data through internet, useful for dispersed work groups allowing remote back-up and heaps more. Most of them are usually compatible with both Windows and Mac Operating systems.
Some of the best selling network hard drives include Iomega IConnect Wireless Network Data Station, 3TB FreeAgent GoFlex Home Network Storage, 6TB Seagate BlackArmour NA S440 and heaps more.
External Hard Drives classification based on OS
Most of the external hard drives are compatible with both Windows and Mac systems. But it is not always the case. There are a lot of External Hard Drives that are being specifically designed for Windows and Mac. Western Digital and Seagate have a separate range for Mac for those Mac lovers out there. Some of the famous external hard drives for Mac include WD My Passport for Mac, WD My Passport SE for Mac, WD My Passport Studio, Seagate GoFlex for Mac Ultra Portable, GoFlex Pro for Mac, etc.