Nine tips for choosing a mobile hard drive

First, capacity

The size of the mobile hard disk capacity is the first choice for many people, usually in GB or TB units, the current market mainstream mobile hard disk capacity has 320GB, 500GB, 1TB, 2TB and so on. The size of the capacity is directly related to the user's storage needs, the choice of mobile hard disk capacity, should be based on their actual needs and product price to decide.

Second, interface type

The interface type is the kind of interface used by the mobile hard disk to connect with the computer system. The current common interface has USB2.0 and USB3.0. The more mature interface technology, the shorter the read data, indicating that the performance of mobile hard disk is better, at present, the USB3.0 interface is absolutely preferred, many businesses also put USB3.0 as an important gimmick, we must learn to distinguish between USB2.0 and 3.0 differences in the purchase!

1, look at the appearance, if the mobile hard disk interface is USB3.0, in the appearance of the box will be marked, and will generally be equipped with USB3.0 icon.

2, look at the interface, to see whether the data line interface is blue, if it is blue for the USB3.0 interface.

3, look at the pins, under normal circumstances USB2.0 is a row of 4 pins, USB3.0 is the front 5 pins, 4 pins in the back row.

4, see Speed, General USB2.0 of the actual transmission speed of mb-40mb/s, and USB3.0 transmission speed can reach 60mb-140mb/s, you need to pay attention to the premise of your computer motherboard support USB3.0.

Third, data transmission rate (data Transfer Rate)

The data transmission rate of mobile hard disk is divided into external transmission rate and internal transmission rate. The external transmission rate refers to the speed at which the computer reads data from the hard disk's cache through an interface, while the internal transmission rate refers to the speed of data transfer between the head of the hard disk and the cache. Because the mobile hard disk is generally external, so the speed of its interface limit the data transmission rate of the mobile hard disk, also means that when you pick a mobile hard drive, the more important to see is the interface of the mobile hard disk data transmission rate, that is, the external transmission rate. The speed of the external transmission rate depends on the interface type of the product. (See Second interface type)

Four, size

At present, the common mobile hard disk size is 3.5-inch, 2.5-inch, 1.8-inch three kinds. One of the 3.5-inch mobile hard disk size and weight are the largest, for the earthquake has no special design, to a certain extent, reduce the security of data, and carry is not convenient, but in terms of price and capacity also have certain advantages.

2.5-inch removable hard drive is more dexterous convenient, the volume weight is small, has the special design in the shockproof aspect, the anti-seismic performance is also good, therefore deeply consumer likes, but compares with the equal capacity 3.5 inch mobile hard disk to compare the price relatively high.

1.8-inch removable hard drive, no problem in the earthquake, size, weight is the smallest, but because of high technical requirements and prices have been high, not yet popular, more suitable for special needs of users.

The speed of the hard drive is also different except for the volume. 1.8 and 2.5 are generally only 5400 rpm, and the majority of 3.5 is 7200. There are also more than 10000, the higher the speed of reading write faster.

V. Caching

Cache memory is a memory chip on the hard disk controller, which has an extremely fast access speed and is the buffer between the internal storage of the hard disk and the external interface. When the hard disk accesses the fragmented data, it is necessary to constantly exchange data between the hard disk and the memory, if there is a large cache, those fragmentary data can be temporarily cached, reduce the load of the external system, and improve the transmission speed of the data.

The size and speed of the cache is directly related to the transmission speed of the important factors, can greatly improve the overall performance of the hard disk, therefore, in the hard drive other parameters almost the same situation, as much as possible to choose the cache large mobile hard disk.

Six, rotate speed

Rotational speed refers to the spindle of the motor drive inside the rotation rate, that is, the hard disk in a minute to complete the maximum number of revolutions per minute to say, the unit for RPM. The greater the RPM value, the faster the internal transfer rate, the shorter the access time, the faster the hard disk looks for files, the better the overall performance of the hard disk. Now the speed of the mobile drive generally has 5400rpm, 7200rpm.

Vii. single disc capacity (storage per disk)

The hard disk consists of one or several platters, and the capacity of the disc refers to the total capacity of each platter including the positive and negative sides. The capacity of a single disc determines the level of the hard disk to a certain extent. The increase in the capacity of a single disc means that the improvement of the development of the manufacturers ' technology brings not only the increase of the hard disk capacity, but also the corresponding improvement of the hard disk performance. The same speed of the hard disk, the larger the capacity of the single disc, the faster the internal data transfer rate, in addition, the increase in the capacity of a single disk to increase the linear density (the number of tracks per inch) has also been improved, which is conducive to the reduction of hard disk seek time.

Viii. average seek times (Average)

Average seek time is the time from which the hard disk is obtained from the command to the data found. It embodies the ability of hard disk to read data to some extent, and it is an important parameter that affects the internal data transmission rate of hard disk. The average seek time is in milliseconds (ms), and the average search time for hard drives is 7.5~14ms. Different brands, different models of products, the average seek time is not the same, but the lower the time, the product is better, the current mainstream hard drive products average seek time in about 9ms.

The average seek time is actually a parameter which is decided by several factors such as rotational speed and single disc capacity. Generally speaking, the higher the speed of the hard disk, the lower the average seek time; the larger the single disc capacity, the lower the average seek time. When the capacity of the single disc increases, the seeking action and the moving distance of the head are reduced, which reduces the average seek time and accelerates the hard disk speed. Therefore, in the purchase of hard disk products should be as far as possible to choose the average seek time short products.

Nine, Brand

Brand, this is in fact only in general, because each brand of consumers will be dissatisfied with the product, the evaluation of the situation. Now the most used is Seagate and the western data two, of course, Samsung also has a lot of people in use, Toshiba seems to have a lot of supporters. Suggest friends in fancy a mobile hard drive, look at the bottom of the buyer's evaluation, do a simple reference.