What is the difference between single-disk and double-disk mechanical hard drives?

Difference: Due to the different structures of mechanical hard drives, single-disk hard drives are lighter, faster, and more stable than double-discs, and are more suitable for users who have certain speed requirements; double-disc hard drives are better than single-disc hard drives. Large capacity, more suitable for users with large storage needs.

Mechanical hard drive

Mechanical hard drive has been developed for nearly 70 years. So far, from the time when a hundred schools of thought contended to being acquired, acquired, and acquired, there are only a few major manufacturers left. Now solid-state drives have begun to rise in an all-round way, and news about HDDs giving way to SSDs is spreading all over the market. , but the author believes that HDD still has a lot of market space. After all, terabyte-level solid-state drives have not yet been fully popularized.

So it is necessary for us to understand the knowledge about HDD. Friends who are familiar with hard drives know that mechanical hard drives are composed of multiple storage discs. The capacity of a single disc we often say is one storage disc. The maximum amount of data that can be stored.

What is the difference between single disc and double disc?

Due to the different structures of mechanical hard drives, single-disk hard drives are lighter, faster, and more stable than double-discs, and are more suitable for users who have certain requirements for speed; double-disk and single-disk It has a large capacity and is more suitable for those with large storage needs.

The difference between single and double disks

Single disk capacity (storage per disk) is a very important parameter of the hard disk. It determines the grade of the hard disk to a certain extent. Hard disk manufacturers are increasing There are two ways to increase the capacity of a hard disk. One is to increase the capacity of a single disk, and the other is to increase the number of storage disks. However, due to the limitations of the overall volume and production cost of the hard disk, the number of disks is limited, and due to the increase in storage density, When the magnetic head and the disk move the same distance, the amount of data read (or written) will increase accordingly. Therefore, compared with multi-disk hard disks, single-disk hard disks still have certain advantages.

Why can’t the hard drive capacity be increased by increasing the disc area?

The consumer market has always been very hungry for capacity. According to estimates by authoritative organizations, the total amount of data that needs to be stored globally by 2025 will be approximately 135ZB. Faced with such a huge storage demand , I believe that many DIY netizens will ask back, why can’t the hard drive capacity be increased by increasing the disc area?

The size should not be any larger

In fact, this is a simple question that can be answered. First, increasing the diameter of the disc means increasing the size of the disc body, which is Considering the internal size of the chassis, it is obviously not a feasible solution. Secondly, due to the precision properties of mechanical hard drives, the distance between the magnetic head and the disc is only a few nanometers. Increasing the size of the disc will greatly reduce its stability under high-speed operation. Physical damage may even occur. Thirdly, the increase in size will cause the hard drive's seek time to be too long. This will increase energy consumption and cause the hard drive's temperature to rise sharply, affecting platform stability. Therefore, this idea is unrealizable.

Parameters you must look at when buying a hard drive

At present, there are very few mechanical hard drive manufacturers left, and they are almost dominated by Toshiba, Western Digital, and Seagate. Therefore, it is relatively simple when purchasing. Just look for these values.

How to buy a mechanical hard drive?

First of all, you can choose the hard disk capacity according to your own needs. Next is the hard disk speed, in RPM. The mainstream speed is currently 7200RPM, and some are 5400RPM. The higher the speed, the faster the transmission speed. Fast, short access time, short seek time, high transmission efficiency, and relatively good performance, but only if you have to tolerate the noise; the third is the hard disk cache. A large cache can reduce the load on the system when transferring files and increase the transfer speed. . However, in the current hard disk environment, the bigger the cache, the better (because of the shingled disk); finally, I will say one more word about the capacity of a single disk. The larger the capacity of a single disk, the greater the density of the tracks, and the more data that can be read by the head in one rotation. The internal transmission speed is faster at the same speed, so when purchasing, try to choose a hard drive with a large single-disk capacity.

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