Basically, a computer has two types of memory, primary memory and secondary memory. Now primary memory is temporary, which is RAM. However secondary memory is permanent, and this deals with storage drives. Every computer needs a place to store their data. Whether that data is photos, documents, video, and audio files, or an operating system.
A computer needs a place to store this data internally on a storage drive. These drives also need to be non-volatile, which means that they will retain the data even if the power is turned off. There are different types of internal storage drives that a computer uses.
- Hard disk Drive/Magnetic hard drives (HDD)
- Solid state Drives (SDD)
- Hybrid Disk Drive
- Hard disk Drive/Magnetic hard drives (HDD)
Hard disk Drive/Magnetic hard drives (HDD)
Lets first talk about magnetic hard drives. Now magnetic hard drives have been around since the beginning of computers. They were introduced by IBM in 1956 and even though they’ve been around for a long time, they are still used today. The hard disk drive is a sealed case that contains magnetic disks and these disks is where the actual data is stored on. These disks rotate at high speeds and as they do, the actuator arm will either write data to the disks or read data from the disks, depending upon what the user wants to do. These magnetic disks can rotate at high speeds of either 5400, 7200, or 10,000 RPM. The typical hard drive that’s used today in desktop computers operates at the 7200 RPM range. A cheaper desktop hard drive operates at 5400 RPM, which is also the speed of a typical laptop hard drive. Higher-end hard drives would operate at 10,000 RPM. However, these higher-end hard drives are not commonly used anymore.
Hard drives today use the serial ATA interface. Now this is a newer standard that is faster than the outdated parallel ATA interface. So instead of data travelling in a parallel path, the data travels in a serial path, which means that the data travels one bit at a time. SATA drives have transfer speeds averaging 6 gigabits per second, which is considerably faster than the old parallel ATA. And hard drives also come in two physical sizes. They come in 3.5 or 2.5 inches. 3.5-inch drives are what desktop computers and servers will use and 2.5-inch drives is what laptops will use.
Solid State Drive (SSD)
Another type of storage device is called an SSD or solid-state drive. These drives have no moving parts, instead of using magnetic disks, these drives use flash memory chips to store data. So, the data transfer is very fast. In addition, since they have no moving parts, they are also very quiet and more energy efficient. SSDs also come in different form factors. They would come in a standard 2.5-inch rectangular form factor or they would come in the newer M.2 form factor. Now both drives store data on flash memory but they connect to the motherboard using different interfaces. The standard 2.5-inch SSD uses the SATA interface just like a hard drive and the M.2 SSD would plug into an M.2 slot.
SSDs are also more resistant to physical shock compared to hard drives, whereas if you were to physically shock a hard drive, such as dropping it or jolting your computer, it could crash the drive and your data would be lost. SSDs are also more expensive than hard drives, but you do get what you pay for because they are considerably faster, and you’ll see a big difference in the performance of your computer. They can also be used on both desktop and laptop computers. Now because of the price difference between SSDs and hard drives, a lot of times if you were to buy a new computer, the computer may come with both an SSD drive and a hard drive. The faster SSD would be a smaller capacity drive that would contain any data that would benefit from the speed and that you would access frequently, such as the operating system, programs, and documents. The slower hard drive would be a larger capacity drive that would be used for secondary storage. For example, to store data that you would access less frequently or the drive would be used to store large files such as videos.
Solid State Hybrid Drive (SSHD)
Now there is also a solution where you can have an SSD and a hard drive as one physical drive instead of two separate drives. These are called SSHD or solid-state hybrid drives. Now these drives combine the use of magnetic disks and flash memory. Hybrid drives take advantage of the large capacity and the low cost of magnetic disks, with the speed of an SSD.
