In addition to flash-based SSDs, other technologies such as 3D XPoint offer faster speeds and higher endurance through different data storage mechanisms.
Unlike traditional hard disk drives (HDDs), SSDs have no moving parts, allowing them to deliver faster data access speeds, reduced latency, increased resistance to physical shock, lower power consumption, and silent operation.
[3] SSDs based on NAND flash slowly leak charge when not powered, while heavily-used consumer drives may start losing data typically after one to two year in storage.
[5] Unlike HDDs and similar electromechanical magnetic storage, SSDs do not have moving mechanical parts, which provides advantages such as resistance to physical shock, quieter operation, and faster access times.
[7][8] Traditional interfaces (e.g. SATA and SAS) and standard HDD form factors allow such SSDs to be used as drop-in replacements for HDDs in computers and other devices.
[16][17] However, SSDs are sensitive to sudden power interruption, sometimes resulting in aborted writes or even cases of the complete loss of the drive.
Combined with a cloud computing environment or other writable medium, an OS booted from a write-locked SD card is reliable, persistent and impervious to permanent corruption.
The flash layer in these drives can be accessed independently from the magnetic storage by the host using ATA-8 commands, allowing the operating system to manage it.
[57] Wear leveling is a technique used in SSDs to ensure that write and erase operations are distributed evenly across all blocks of the flash memory.
This cache can temporarily hold data while it is being written to the flash memory, and it also stores metadata such as the mapping of logical blocks to physical locations on the SSD.
[82] In certain high-end consumer and enterprise SSDs, larger amounts of DRAM are included to cache both file table mappings and written data, reducing write amplification and enhances overall performance.
[84] Higher-performing SSDs may include a capacitor or battery, which helps preserve data integrity in the event of an unexpected power loss.
[87] Some consumer SSDs have built-in capacitors to save critical data such as the Flash Translation Layer (FTL) mapping table.
The benefit of using a current HDD form factor would be to take advantage of the extensive infrastructure already in place to mount and connect the drives to the host system.
It remains electrically compatible with the PCI Express Mini Card interface specification while requiring an additional connection to the SATA host controller through the same connector.
While mSATA took advantage of an existing form factor and connector, M.2 has been designed to maximize usage of the card space, while minimizing the footprint.
DOM devices emulate a traditional hard disk drive, resulting in no need for special drivers or other specific operating system support.
DOMs are usually used in embedded systems, which are often deployed in harsh environments where mechanical HDDs would simply fail, or in thin clients because of small size, low power consumption, and silent operation.
As of 2016,[update] storage capacities range from 4 MB to 128 GB with different variations in physical layouts, including vertical or horizontal orientation.
[104] At least one manufacturer, Innodisk, has produced a drive that sits directly on the SATA connector (SATADOM) on the motherboard without any need for a power cable.
The main benefits of BGA SSDs are their low power consumption, small chip package size to fit into compact subsystems, and that they can be soldered directly onto a system motherboard to reduce adverse effects from vibration and shock.
[135] While the storage capacity was limited and the price high (around $1,000), this marked the beginning of a transition to flash memory as an alternative to traditional hard drives.
[130] Enterprise flash drives (EFDs) are designed for high-performance applications requiring fast input/output operations per second (IOPS), reliability, and energy efficiency.
Designed for write-intensive applications like online transaction processing, these drives achieved impressive read and write speeds and high endurance ratings.
Unlike NAND flash, 3D XPoint uses a different method to store data, offering higher IOPS performance, although sequential read and write speeds remain slower compared to traditional SSDs.
The first flash-memory SSD based PC to become available was the Sony Vaio UX90, announced for pre-order on 27 June 2006 and began shipping in Japan on 3 July 2006 with a 16 GB flash memory hard drive.
Some log-structured file systems (e.g. F2FS, JFFS2) help to reduce write amplification on SSDs, especially in situations where only very small amounts of data are changed, such as when updating file-system metadata.
Linux swap partitions are by default performing discard operations when the underlying drive supports TRIM, with the possibility to turn them off.
However, because TRIM irreversibly resets all freed space, it may be desirable to disable support where enabling data recovery is preferred over wear leveling.
[208] Windows 7 also includes support for the TRIM command to reduce garbage collection for data that the operating system has already determined is no longer valid.