The Most Common Types of Hard Drive Interfaces

Content:
Hard Disk Drive - IDE Interface
Hard Disk Drive - SATA Interface
Solid State Drive - SATA Interface
Solid State Drive - M.2 Interface
Solid State Drive - U.2 Interface
Conclusion

Computers have two types of storage units: temporary and permanent. The temporary storage unit is used for data buffering and is known as the memory module. On the other hand, the permanent storage unit is used for data storage and is known as the hard drive(hard disk/hard disk drive).

When we frequently use computers, we inevitably accumulate a vast amount of data that we need to save. As our storage space decreases, we need to expand it. However, if we don't know the interface type of our hard disk, we may not know how to expand our storage space.

For instance, if you have a desktop computer, you need to know the hard drive interface types supported by the motherboard before purchasing a hard drive. Similarly, if you have a laptop, you may want to buy a portable mobile hard drive or assemble one by yourself (which requires buying a hard drive and a hard drive enclosure). At this point, you might want to know which hard drive is more portable and has faster data transfer. In this article, you will learn about common hard disk interfaces and their development history.

Hard Disk Drive - IDE Interface

The IDE interface, which stands for "Integrated Drive Electronics," is an old but widely used standard electrical interface between the hard drive and the motherboard of a computer. The IDE interface has the following appearance:

One of the key benefits of the IDE interface is that it integrates the hard disk controller with the hard disk body, which reduces the number and length of interface cables, improves data transmission reliability, and simplifies the manufacturing and installation of the hard disk.

The IDE interface supports parallel data transmission and comes in 40-pin and 80-pin forms. It is often used interchangeably with the term "ATA interface" (which stands for "Advanced Technology Attachment"). However, SATA (Serial ATA) has replaced the IDE interface due to its advanced technology.

Despite being obsolete, the IDE interface is still used in some areas because it is relatively inexpensive and highly compatible.

Hard Disk Drive - SATA Interface

The bandwidth provided by IDE was not sufficient to meet the growing needs of hard disk drives. So, the SATA interface was created, and IDE was renamed PATA. In 2013, all hard drive manufacturers officially stopped producing PATA hard drives.

SATA is short for Serial ATA. It has several advantages over PATA, including support for hot swapping, faster transmission speeds, and stronger error correction capabilities. These improvements greatly enhance the reliability of data transmission. Additionally, SATA cables are thinner and simpler, making it easier for users to install them on their computers. This also facilitates air circulation inside the computer chassis, increasing the overall stability of the platform. The SATA interface has the following appearance:

Both IDE and SATA hard drives are hard disk drives containing mechanical components. The internal structure of a hard disk drive includes a disc as a storage medium, and a mechanical arm and head movement to locate data points.

Hard disk drives have a limit to the data reading and writing speed due to bottlenecks in mechanical displacement and disk rotation speed. Additionally, mechanical components are very precise and can be easily damaged by vibration, and data may be lost if the power is unexpectedly cut off.

The SATA interface has undergone three generations of changes, each with improved performance. Below are the theoretical reading speeds and bandwidths of each generation:
- SATA 1.0 has a theoretical read and write rate of 150MB/s and a bandwidth of 1.5Gb/s.
- SATA 2.0 has a theoretical read and write rate of 300MB/s and a bandwidth of 3Gb/s.
- SATA 3.0 has a theoretical read and write rate of 600MB/s and a bandwidth of 6Gb/s.

Solid State Drive - SATA Interface

Solid State Drives (SSDs) were invented due to the limitations of mechanical hard drives. SSDs are hard drives that use an array of solid-state electronic memory chips. They have higher read and write speeds, lower energy consumption, higher shock resistance, and longer service life when compared to traditional hard disk drives (HDDs).

However, some people believe that this technology is a transitional stage and that it doesn't fully utilize the advantages of solid-state memory. They think that SSDs are a concession made to be compatible with the SATA interface.

Solid State Drive - M.2 Interface

For users with desktop computers, a hard drive using a SATA interface is usually enough to satisfy their needs. However, when it comes to lighter laptops, users require a smaller yet faster hard drive. This is where the M.2 SSD comes into play. The M.2 interface has the following appearance:

The M.2 drive is also known as the Next Generation Form Factor (NGFF), which is a new standard introduced by Intel to replace the MSATA drive. Due to its smaller size and faster speed, most laptops nowadays use hard drives with this interface. In terms of speed, it is comparable to the memory module, and it looks similar to memory as well.

Solid State Drive - U.2 Interface

Solid-state drives nowadays come in different interfaces, including SATA3.0, M.2, and U.2. U.2 is an interface specification introduced by the SSD Form Factor Work Group. It is also known as SFF-8639. U.2 interface is compatible with various specifications such as SAS, SATA, and SATA-Express. It can be compared to the SATA-Express interface, but with four channels and a theoretical bandwidth of up to 32Gbps, similar to M.2. The U.2 interface has the following appearance:

The U.2 solid-state drive has a similar shape to SATA and has the same volume as a SATA hard drive. It is usually 2.5 inches in size and is commonly used for server interfaces.

Conclusion