Difference Between SSD and HDD

What is SSD?

In the past few decades, computer hardware has undergone several significant changes. The transition from spinning discs to solid-state drives (SSD) for storage has been one of the most significant developments. The effects of this on computer performance as a whole are numerous.

However, they are speedier than HDDs since the data is stored on interconnected flash memory chips rather than platters. Therefore, compared to HDD, it has better performance. SSD solid-state flash memory is a more recent innovation in computer storage. Data is stored permanently, which means it is kept even when the power is turned off.

In contrast, conventional hard disc drives need the power to continue spinning to preserve the integrity of the data stored on them. In addition, because an actual read head is not there, SSDs are also faster than HDDs.

In SSD, all components may be accessed in the same amount of time, eliminating variable seek time and rotational delay. In addition, SSD write speeds are significantly slower than read speeds, which results in rapid data access.

 It may store one bit of data at a time in the individual NAND cells that make up SSD storage, which is then grouped into pages. Additionally, pages are arranged into blocks. Since they are more mobile-friendly and much more suited for constant travel, SSDs contain lightweight components or moving elements.

What is HDD?

Since HDDs are a form of non-volatile storage, the information stored on them can be maintained without electricity. A hard disc drive is a type of data storage that uses quickly rotating discs covered in a magnetic material to store and retrieve digital data.

The platters are paired with magnetic heads that read and write data to the platter surfaces. These heads are typically positioned on a moving actuator arm. As a result, data is accessed randomly, allowing for storing or retrieving discrete blocks of data in any order, not just sequentially.

A non-volatile storage device is an HDD, which keeps its data even after the power is turned off. Hard disc technology is a relatively old development. The 1956 IBM 650 RAMAC hard drive featured 50 24-inch-wide platters and could hold an astounding 3.75MB of data.

Unfortunately, the RAMAC 350 was only employed by the government and businesses by 1969 since it had outlived its usefulness. Large amounts of data can be stored on the HDD, a data storage device. It is a frequently utilized technology that is reasonably priced and essential.

Data is kept on rotating drives. The rotating discs have magnetically encoded data. Data may be kept on a revolving platter of an HDD due to magnetism. It has a memory (ROM head) that reads and writes data and floats above the rotating platter. An HDD can operate more quickly the faster the platter spins. HDDs also include firmware and I/O controls.

Difference Between SSD and HDD

The difference between SSD and HDD is the absence of moving elements in SSD as compared to HDD’s use of spinning platters. Therefore, SSD is quicker than HDD. The price differential between SSD and HDD is another way they differ.

The standard form of storage for desktop and laptop computers is hard drives. They are slower because they are more significant than solid-state drives, but they can store more data. Additionally, they are less expensive than SSDs. 

Although SSDs use flash memory, HDDs store data on rotating discs. Flash memory is a non-volatile memory that does not need electricity to keep the information inside. As a result, SSDs often operate at a higher speed and with less power than HDDs.

Comparison Between SSD and HDD

Parameter of ComparisonSSDHDD  
Full FormSolid State DriveHard Disk Drive  
ElementsOnly electronic components (ICs)Includes mechanically active moving elements (Arm)  
R/W DurationShorterLonger  
LatenciesLower LatencyHigher Latency  


  1. https://ieeexplore.ieee.org/abstract/document/5485421/
  2. https://www.diva-portal.org/smash/record.jsf?pid=diva2%3A824922&dswid=483