How to choose a mechanical hard drive, CMR or SMR?

Although higher speed solid-state drives (SSDs) have become popular, mechanical hard drives with the same capacity have the advantages of low price and easy recovery, which SSDs cannot match. Therefore, due to cost considerations, many users choose mechanical hard disks as large-capacity storage disks to store some infrequently read and write but bulky things. At the same time, in the company, most of the office computers are mainly desktops, and most of them are also mainly mechanical hard disks. This can greatly reduce the company's hardware procurement costs, so SSDs cannot replace mechanical hard disks in a short period of time!

Mechanical hard disk brand selection

At present, there are three main brands of mechanical hard drives: Western Digital, Seagate, and Toshiba. Just look for these three major brands when purchasing.

Which is better, CMR or SMR?

What is the difference between CMR and SMR? They are two different recording methods of mechanical hard disk, the specific differences are as follows:

Conventional Magnetic Recording, referred to as CMR (also known as conventional magnetic recording), the hard disk using this recording technology will leave a guard gap between the tracks, and the tracks are arranged horizontally, and the data will not be overwritten repeatedly, which is more secure and stable. It is suitable for occasions with frequent data reading and writing, such as video clips and large-scale games.

Shingled Magnetic Recording (SMR for short), this technology is to stack the magnetic tracks in the hard disk like tiles to increase the number of magnetic tracks and increase the storage density of the hard disk. However, SMR is not suitable for rewriting data frequently. Because the read head is small, the write head is large, and the SMR tracks are stacked together, it will affect the write operation of the disk. When randomly writing or rewriting content, the adjacent tracks will also be changed together. To rewrite the content, it is necessary to dump the content of the entire area where the data is located into the cache, modify it in the cache, and write it back to the track together. Due to frequent erasing and dumping, the stability, performance, and lifespan of SMR are relatively poor, and it is generally used as a backup disk/warehouse disk (infrequent reading and writing).

How to identify CMR and SMR?

Not all manufacturers will mark CMR type and SMR type on the hard disk label. Even if it is the same company, some will mark it, and some will not. If CMR is marked separately, it means that the manufacturer regards it as one of the selling points Promote prominently. If it is not marked, it basically defaults to the SMR style.

How to choose a mechanical hard drive? What is the difference between CMR and SMR?

As a buyer, we can try to roughly identify them in the following ways:

  1. Capacity. The CMR type can achieve a single 1.6TB, so the mechanical hard drives less than or equal to 1TB on the market are basically CMR. Cost reduction is one of the important reasons for shingling, so SMRs of the same brand and capacity are cheaper than CMRs.
  2. Cache. Generally speaking, for SMR hard disks, in order to make up for performance defects, the manufacturer equips a larger cache, usually 128MB or 256MB; while the CMR cache is relatively small, usually 32MB or 64MB. However, this method is not accurate, because a large-capacity CMR hard disk (such as a capacity above 4TB) may also use a 256MB cache.

Look at the speed

At present, there are only 5400 rpm and 7200 rpm on the market. The faster the speed, the stronger the performance, and the faster the reading and writing speed, but at the same time, the power consumption is greater and the noise is greater.

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