In this blog post, we will compare the structures and advantages and disadvantages of SSDs and HDDs, and guide you on how to choose the right one for your needs based on the differences in speed and capacity offered by each storage device.
Have you ever lost your hard work due to an unexpected battery drain while working on your computer? If you’ve experienced this, you know how frustrating and disappointing it can be. To prevent such accidents, we must place importance on data storage when using computers and use secure data storage devices. Since IBM established the standard for personal computers in 1981, we have been storing data on devices called hard disk drives (HDDs). The term HDD may be unfamiliar, but you are probably familiar with another name for HDDs: hard disks. However, about five years ago, the term SSD (Solid State Drive) began to replace HDD. Let’s learn about SSDs and compare the structures and advantages and disadvantages of SSDs and HDDs to find out which information storage device is right for you.
Before explaining SSDs, let’s learn about HDDs, which we have used to store information until now. The basic principle of HDDs is to record information on magnetic material. For this purpose, there is a metal disc inside the HDD, and the surface of this disc is covered with a magnetic material. The HDD rotates this disc at high speed while moving a device called an actuator arm slightly above the disc. At the end of the actuator arm is a device called a head, which records or deletes data directly onto the magnetic material on the disc.
The structure of HDDs has not changed significantly since they were first released. However, as people have come to require larger storage capacities, several minor changes have been made to the structure of HDDs. These changes are related to the advantages of HDDs. First, the magnetic material on the internal disk of the HDD was arranged more finely, and the movement of the head was made more precise. As a result, HDDs now have a very large storage capacity, approaching TB (terabyte, 1 TB = 1024 GB). In addition, the rotation speed of the disk was increased, which accelerated the information input/output speed of the HDD. Finally, HDDs reflecting these changes were mass-produced, resulting in HDDs with large storage capacity, fast information input/output speed, and low price relative to storage capacity.
However, these changes are also related to the disadvantages of HDDs. Increasing the rotation speed of the disk to achieve faster information input/output speeds increases the power consumption and noise of the HDD. In order to store large amounts of information, disks larger than a certain size are required, which is a major obstacle to the miniaturization of HDDs. In addition, the basic principle of HDDs is also a cause of their disadvantages. Since HDDs store information on magnetic materials, placing magnetic devices or objects near them can cause the magnetic material to become misaligned, resulting in information corruption or deletion. Furthermore, since the head moves over the disk with a very small gap, external shocks can cause the head to collide with the disk, resulting in permanent damage to the HDD.
SSD (Solid State Drive) is a next-generation information storage device that was developed to address these disadvantages of HDD. The basic principle of SSD is to store information on a semiconductor. SSDs are classified into RAM-based SSDs and flash memory-based SSDs depending on the type of semiconductor used. However, RAM-based SSDs have not been commercialized due to a fatal disadvantage in that the information is lost when the power is turned off. On the other hand, flash memory-based SSDs are suitable as secure information storage devices because the information is retained even when the power is turned off, and have been commercialized. Generally, the term SSD refers to flash memory-based SSDs, and this article will follow suit.
Most of the advantages and disadvantages of SSDs are due to the characteristics of semiconductors mentioned above. The advantage of SSDs is that they can compensate for almost all of the disadvantages of HDDs. Unlike HDDs, SSDs do not require physical movement to record information. As a result, SSDs consume less power and produce less noise than HDDs. In addition, the semiconductors inside SSDs have information input/output speeds that cannot be matched by the physical methods used in HDDs, and they are easy to miniaturize and resistant to shock.
Looking only at the above advantages, one may wonder why SSDs have not yet completely replaced HDDs. This is because SSDs have disadvantages in terms of price and capacity. Although prices vary depending on product performance, as of October 2016, a 256GB SSD can be purchased for around 140,000 won, which is enough to buy a 2TB HDD. Unlike HDDs, SSDs are expensive compared to their storage capacity, and there are few large-capacity products in the TB range on the market.
These disadvantages can be sufficiently resolved with the advancement of technology over time. Therefore, there will come a time when SSDs will completely replace HDDs. However, what should we do now, as we are not yet living in that era? Some people blindly prefer new technologies as soon as they appear, but we would like to warn against this attitude. Of course, if you plan to use your computer simply for web surfing or document work, SSDs with fast information input and output speeds can provide a pleasant user experience. However, if you plan to use games or programs that require a lot of storage space, large-capacity HDDs may be the better choice. We hope that readers of this article will carefully consider the advantages and disadvantages of HDDs and SSDs and choose the storage device that best suits their needs.
