Which brand of mobile hard disk is good? What brand of mobile hard disk is good?

What brand of mobile hard disk is good? Those brands are better. I want to find the information I want to know. There are many ways to do it. The easiest way to go to the Taobao popularity ranking network is to let you buy it there. The key is to look at the comments of the netizens. So you can know what is the best and best for your mobile hard drive. It must be said that it is really good.

You can make a reference, then you can go to a nearby mall to buy, but the price will be more expensive, there must be some expenses in it. I personally think that many Dongdong purchases on the Internet are still very suitable, but they are not absolute and should vary from person to person. What brand of mobile hard disk is good, or depends on its performance. 2013 latest rain forest wood wind xp system download: rain forest wood wind Ghost XP sp3 2013 pure version

What are the technical indicators that affect hard disk performance?

1, speed

What brand of mobile hard disk is not the deciding factor, the main thing is to look at its speed. There is no doubt that speed is the most compelling performance parameter in addition to capacity in all of the hard drive's specifications. When any hard disk is available, its propaganda material will mention its speed in the first article. The speed has a great influence on the speed of the hard disk and the continuous transmission speed. I have a special discussion on the mechanism of this issue, which will not be repeated here. Currently, IDE hard drives are mainly composed of two series: 5400RPM and 7200RPM.

2, single-disc capacity

If the rotational speed is the first element of hard disk performance, then the second place should undoubtedly be the magnetic recording density of the disk surface. Because the current desktop IDE hard drive shell generally can only put up to 4 discs, only IBM can put 5 sheets. Obviously, it is not feasible to increase the capacity of the disc to meet the growing demand for storage capacity. Only by increasing the capacity of each disc can this problem be solved fundamentally. The standard size of a desktop IDE hard drive is 3.5 inches (disk diameter), so the density of magnetic recording must be increased. However, as the density of the disk increases, the head must become more sensitive. The maximum single disc capacity that a conventional MR head can withstand is about 4.5G. At present, all the hard disks with a single disc capacity exceeding 5G have already used the GMR head.

In addition to the contribution to capacity growth, another important significance of single-disc capacity is to increase the data transfer speed of the hard disk. The increase in single-disc capacity is due to the increase in the number of tracks and the increase in linear magnetic density in the track. The increase in the number of tracks is advantageous for reducing the seek time of the magnetic head because the radius of the magnetic disk is fixed, and the increase in the number of tracks means the shortening of the distance between the tracks, and the transfer of the magnetic head from one track to the other is required. The bit time will be shortened. This will help increase the speed of random data transmission. The increase in linear magnetic density in the track is directly related to the sustained data transfer speed of the hard disk. Because the current IDE hard disk does not need an interlacing factor, the target data in the track where the head is located will be read once each time the disk passes a circle under the head. The increase in linear density within the track allows more data to be stored in each track, so that more data is read from the head into the buffer of the hard disk in each circular motion of the disk. The new generation of GMR head technology ensures that this growth does not slow down due to the sensitivity of the head. This is why, in many cases, the higher single-disc capacity of the 5400RPM hard drive has a higher performance than the 7200RPM hard drive with a lower single-disc capacity.

Therefore, the single-disc capacity of the disk is the second largest performance parameter after the speed. It directly determines the continuous data transmission speed of the hard disk. The most obvious difference between the different generations of the 5400RPM and 7200RPM series is the single-disc capacity.

3. Average seek time

This is the average time the head reaches the track where the target data is located. This time and the average latency of the head (determined entirely by the speed) determine the time at which the hard disk head finds the cluster in which the data resides. This time directly affects the random data transmission speed of the hard disk. In addition to the single-disc capacity described above, the average determinant of the head is the operating speed of the head power arm. In the current mainstream hard drive, in addition to Xijie's ATA cool fish is slightly faster than 7.6 milliseconds. The mainstream models of the remaining brands are basically 8.5 to 9 milliseconds.

4. Data Cache

In addition to the three factors mentioned above, increasing the capacity of the hard disk cache is also a shortcut to improve the overall performance of the hard disk. Due to the internal data transfer speed of the hard disk (data from the disc to the cache speed) and the interface transfer speed (from the hard disk cache to the system main memory speed). So you need a cache to make a speed adapter. The performance of the cache on the performance of the hard disk is mainly manifested in the following two aspects:

In the process of reading the data, the control chip in the hard disk issues an instruction to the system command to read the adjacent cluster. The next or several clusters of data are read into the hard disk cache. When the system command starts to read the data of the next cluster, the hard disk does not need to restart a read operation, and only needs to transfer the data in the cache to the system. It’s fine to go to the main deposit. Because the data transfer from the hard disk cache to the system main memory is only electronic motion, the speed is much faster than the mechanical action required for the hard disk to perform the read operation. Since the storage of data on the disk is relatively continuous, the hit rate of this pre-read next cluster is very high. An increase in the cache capacity allows more pre-read data to be accommodated.

In the operation of writing data to disk, the data is first written to the cache from the system main memory. Once this operation is completed, the system can move to the next operation instruction without waiting for the data in the cache to be written. The completion of the operation of the disc. The time that the system waits is greatly reduced. The increase in cache capacity allows more system latency to be saved. Therefore, the size of the buffer has a great impact on the sustained data transfer speed of the hard disk. Therefore, the cache of mainstream hard disks on the market has almost been added to 2M. And the new products of each company are more to convey the product positioning to the market through the cache capacity. The 2M cache specification is the mainstream model, and the 512K cache is undoubtedly a cheap model positioned in the low-end market.

5, interface type

interface is also an important factor affecting the performance of the hard disk, it directly affects the maximum external data transmission supported by the hard disk, and now the mainstream hard disk interface type is Ultra ATA/66 The latest ATA interface is Ultra ATA/100. Since the introduction of the Ultra ATA/66 interface standard in 1998, almost all new IDE hard drives now support DMA66 without exception. However, due to the limitations of hard disk platters and disk technology, the internal data transfer rate and continuous data transmission of the hard disk can not reach 66MB/s. Now the transmission rate of the general hard disk is between 35~45MB/s, so so far The full power of Ultra ATA/66 cannot be fully utilized.

6. Data Protection Mechanism

As the capacity and speed of hard disks increase, people's requirements for hard disk security are also increasing. As a result, companies have developed data protection systems, the most distinctive of which is the data guards of Western Digital. The technology is based on SMART, but is independent of SMART, and the specific work process is somewhat similar to Microsoft's ScanDisk (&"Data Guardian" technology is fully compatible with SMART and ScanDisk), but more automated: when the hard drive After the accumulated power is up to 8 hours, once the system is idle for more than 15 seconds, the hard disk can automatically detect and repair the wrong data. If the scanning process is interrupted due to system recovery or shutdown during the scanning process, the hard disk will be idle again in the system (or Idle after powering on) After 15 seconds, continue scanning until the task is completed. Perform a full scan, which takes only 8 minutes for a 4.3G hard drive and 20 minutes for a 13G hard drive. It is a good assistant to protect hard drive data. 2013 latest deep technology xp system download: deep technology Ghoat XP SP3 2013 fast installed version

In addition, there are IBM DFT (Drive Fitness Test) and Quantum's DPS (data protection system, Data Protection System), MAXTOR's MaxSafe and XJ's 300G anti-collision design. These protection mechanisms are similar. What brand of mobile hard disk is not the main factor to choose the hard disk, or depends on its performance, good hard disk performance is excellent, this is the main factor for your choice of hard disk.