Solid-state drive

An SSD helps a computer remember things.

It uses tiny parts to store data. These parts do not move. Because they do not move, the drive is very quiet. It can also work very fast.

This drive is also strong. It can handle being bumped or shaken. You can find them in many things. They are in computers and phones. Some even look like small sticks.

They are great for making devices work well.

An SSD is a way for computers to store data. SSD stands for solid-state drive.

Unlike old hard drives, an SSD has no moving parts. It uses tiny parts called integrated circuits to hold information. Because nothing spins or moves, these drives are very quiet. They are also very fast at finding data.

They can also handle being bumped or shaken.

Most SSDs use NAND flash memory. This is a type of memory that keeps data even when the power is off. Inside the drive, data sits in tiny memory cells. Some cells store only one bit of data. We call these single-level cells, or SLC. Other cells can store more data. These are called multi-level cells. Using more bits per cell makes the drive cheaper. However, it can also make the drive slower.

SSDs are used in many things. You can find them in laptops and mobile phones. Some SSDs are very small. They can look like tiny sticks. They are often used to make computers work much faster.

A solid-state drive, or SSD, is a special way for computers to store information.

It uses tiny electronic parts called integrated circuits to keep data safe. You might also hear people call it a semiconductor storage device. These drives are very important because they help our devices work quickly. They are used in many things like personal computers and mobile phones. They are also used in huge enterprise servers.

Most SSDs work using a type of memory called NAND flash. This memory is non-volatile, which means it keeps data even when the power is turned off. Inside the drive, data is kept in tiny memory cells. The way these cells work can change how fast the drive is. Single-level cells, or SLC, store just one bit of data per cell. This makes them very fast and strong. Other types, like quad-level cells (QLC), store more bits in each cell. These are more affordable but they work more slowly.

In the past, computers mostly used hard disk drives (HDDs). These older drives have moving parts that spin to find data. SSDs are different because they have no moving parts at all. This makes them much faster at finding information. They are also very quiet because nothing is spinning inside. Because they do not have moving parts, they can handle being bumped or shaken easily. This makes them very rugged.

There are many different shapes and speeds for SSDs. Some use a connection called SATA, while others use faster ones like PCIe and NVMe.

Some special drives use 3D XPoint technology to work even faster. This technology changes electrical resistance to store data. As of late 2025, a 4TB SSD might cost between $0.05 and $0.10 per gigabyte. This is more expensive than an HDD, which costs about $0.01 to $0.03. However, SSDs can reach huge sizes up to 245.76TB.

SSDs are a big part of how we use technology today. You might see them in a tiny form factor like an M.2 stick. Some people even use hybrid drives, called SSHDs, to get the best of both worlds. These combine SSD technology with traditional spinning disks. This helps the computer find important data much faster. Even though they can wear out after many years of use, they are replacing old drives everywhere.

A solid-state drive, or SSD, is a high-performance storage device. It uses integrated circuits to store data persistently. This means the information stays safe even when the power is turned off. These devices are also called semiconductor storage devices or solid-state disks. SSDs are essential for modern technology because they provide fast data access. They are found in personal computers, mobile devices, and massive enterprise servers.

Most SSDs function using a type of non-volatile memory called NAND flash. This memory stores data within tiny components called memory cells. The performance and endurance of the drive depend on how many bits are stored in each cell. Single-level cells, or SLC, store only one bit per cell. This design makes them very fast and durable. In contrast, multi-level cells (MLC), triple-level cells (TLC), and quad-level cells (QLC) store more bits per cell. While these allow for more storage, they generally have lower performance and endurance.

Some advanced drives use different mechanisms to achieve even higher speeds. For example, 3D XPoint technology, used in Intel's Optane, offers faster speeds and higher endurance. Instead of storing electrical charges in cells like NAND flash, 3D XPoint changes electrical resistance to store data. This method allows for faster data access and longer persistence. Furthermore, SSDs use internal parallelism to manage multiple operations at once. This ability to handle many tasks simultaneously greatly enhances their overall performance.

SSDs differ significantly from traditional hard disk drives (HDDs) because they have no moving parts. HDDs are electromechanical devices that use spinning magnetic disks and moving heads to find data. Because SSDs are entirely electronic, they offer much lower latency and higher input/output rates (IOPS). They are also much more rugged and resistant to physical shock. Additionally, SSDs operate silently and consume much less power. High-performance SSDs use only about one-third to one-half of the power required by HDDs.

There are many ways to connect an SSD to a computer system. Older interfaces like SATA and SAS allow them to act as direct replacements for HDDs. Newer, faster interfaces include NVM Express (NVMe) over PCI Express (PCIe). There are also many different physical shapes, called form factors. These include mSATA, M.2, U.2, and the EDSFF. Some hybrid solutions, known as solid-state hybrid drives (SSHDs), combine SSD and HDD technologies. Examples include Intel's Hystor and Apple's Fusion Drive, which use flash memory to speed up frequently accessed data.

While SSDs are very reliable, they do have specific limitations. Every SSD has a finite number of write cycles, meaning the cells eventually wear out. To manage this, controllers use complex wear-leveling algorithms to spread data across the drive. If an SSD reaches its maximum terabytes written (TBW), it may lose data more quickly. For instance, a 1 TB Samsung 970 EVO has an endurance rating of 600 TBW. Additionally, NAND flash can slowly leak charge when unpowered. A consumer drive might lose data after one to two years if left unpowered in storage.

Comparing costs and capacities shows why HDDs are still used for some tasks. As of late 2025, SSDs cost roughly $0.05 to $0.10 per gigabyte for large 4TB or 8TB models. HDDs are much cheaper, costing only $0.01 to $0.03 per gigabyte for the same capacity. However, SSDs offer much higher maximum capacities, reaching up to 245.76TB. In terms of speed, consumer SSDs can reach transfer rates between 200 MB/s and 14,800 MB/s. This is vastly superior to the roughly 200 MB/s typical of many HDDs.