External hard disk is composed of a regular notebook hard drive (core) and mobile hard disk box (shell). HDD enclosure construction principles are very simple, just through the master chip transformed the SATA interface of 2.5-inch hard drive into USB 2.0 port or SATA port, it will be OK. Therefore, the transmission performance of external hard disk drive not only depends on the performance of built-in hard disk, but also depends on the SATA to USB host chip performance.
There are a variety of external hard disks, according to volume; it can be divided into 3.5-inch external hard disk, 2.5-inch external hard disk, as well as 1.8-inch external hard disk. Of which 3.5-inch are bulky and need to connect an external power supply, portable is poor; 1.8-inch have small size and low consumption, small capacity, Unfortunately, poor performance and the price is slightly higher, compared with the U disk, it have no advantage, resulted in 1.8-inch external hard disk slow development of embarrassment recent years. The remaining 2.5-inch positioned between the former two types of external hard disk, and it is the mainstream external hard disk type.
According to brands, external hard disk can be divided into three types: original, brand and DIY, original means that the hard drive are offered from the major manufacturers, such as Hitachi NESO, Western Digital and Maxtor, etc.; Brand External Hard reality is those built-in other brand products, like Yi Jie, BenQ, Li Jie, etc; DIY means fabricated the hard drive purchased separately together with the hard case.
Consumers went to purchase external hard drives often do not know which type he should choose. If the budget is adequate, the best choice is original external hard disk, these drives are not only stable, value-added feature-rich, and often have a better shape, of course, brand also has this advantage, it’s more benefits than the original external Hard, but it’s better to select a good brands when purchasing, not to fall into the trap of external hard disk cottage. However, the DIY have a high cost-effective, if you have less budget, it’s an excellent choice, it could help you get a greater capacity, so it’s more popular with students.
