A hard disk drive (HDD), hard disk, hard drive, or fixed disk is an electro-mechanical data storage device that stores and retrieves digital data using magnetic storage with one or more rigid rapidly rotating platters coated with magnetic material. The platters are paired with magnetic heads, usually arranged on a moving actuator arm, which read and write data to the platter surfaces. Data is accessed in a random-access manner, meaning that individual blocks of data can be stored and retrieved in any order. HDDs are a type of non-volatile storage, retaining stored data when powered off. Modern HDDs are typically in the form of a small rectangular box.
Flash memory is an electronic non-volatile computer memory storage medium that can be electrically erased and reprogrammed. The two main types of flash memory, NOR flash and NAND flash, are named for the NOR and NAND logic gates. Both use the same cell design, consisting of floating-gate MOSFETs. They differ at the circuit level depending on whether the state of the bit line or word lines is pulled high or low: in NAND flash, the relationship between the bit line and the word lines resembles a NAND gate; in NOR flash, it resembles a NOR gate.
Western Digital Corporation is an American data storage company headquartered in San Jose, California. It has a decades-long history in the electronics industry as an integrated circuit and data memory technology developer. It is one of the world's largest computer hard disk drive (HDD) manufacturers, along with producing solid-state drives (SSDs) and flash memory devices.
Seagate Technology Holdings plc is an American data storage company. It was incorporated in 1978 as Shugart Technology and commenced business in 1979. Since 2010, the company has been incorporated in Dublin, Ireland, with operational headquarters in Fremont, California, United States.
Self-Monitoring, Analysis, and Reporting Technology is a monitoring system included in computer hard disk drives (HDDs) and solid-state drives (SSDs). Its primary function is to detect and report various indicators of drive reliability, or how long a drive can function while anticipating imminent hardware failures.
SanDisk LLC is an American multinational computer technology company based in Milpitas, California. It is known for its flash memory products, including memory cards and readers, USB flash drives, solid-state drives, and digital audio players. The company was founded in 1988 as SunDisk Corporation and renamed in 1995 as SanDisk Corporation; it assumed its current name in 2016 when it was acquired by Western Digital.
Input/output operations per second is an input/output performance measurement used to characterize computer storage devices like hard disk drives (HDD), solid state drives (SSD), and storage area networks (SAN). Like benchmarks, IOPS numbers published by storage device manufacturers do not directly relate to real-world application performance.
A hybrid drive is a logical or physical computer storage device that combines a faster storage medium such as solid-state drive (SSD) with a higher-capacity hard disk drive (HDD). The intent is adding some of the speed of SSDs to the cost-effective storage capacity of traditional HDDs. The purpose of the SSD in a hybrid drive is to act as a cache for the data stored on the HDD, improving the overall performance by keeping copies of the most frequently used data on the faster SSD drive.
OCZ was a brand of Toshiba that was used for some of its solid-state drives (SSDs) before they were rebranded with Toshiba. OCZ Storage Solutions was a manufacturer of SSDs based in San Jose, California, USA and was the new company formed after the sale of OCZ Technology Group's SSD assets to Toshiba Corporation. Since entering the memory market as OCZ Technology in 2002, the company has targeted its products primarily at the computer hardware enthusiast market, producing performance DDR SDRAM, video cards, USB drives, power supply units, and various cooling products.
In 1953, IBM recognized the immediate application for what it termed a "Random Access File" having high capacity and rapid random access at a relatively low cost. After considering technologies such as wire matrices, rod arrays, drums, drum arrays, etc., the engineers at IBM's San Jose California laboratory invented the hard disk drive. The disk drive created a new level in the computer data hierarchy, then termed Random Access Storage but today known as secondary storage, less expensive and slower than main memory but faster and more expensive than tape drives.
A solid-state drive (SSD) is a type of solid-state storage device that uses integrated circuits to store data persistently. It is sometimes called semiconductor storage device, solid-state device, or solid-state disk.
Phison Electronics Corporation is a Taiwanese public electronics company that primarily designs, manufactures and sells controllers for NAND flash memory chips. These are integrated into flash-based products such as USB flash drives, memory cards, and solid-state drives (SSDs).
In electronics, a multi-level cell (MLC) is a memory cell capable of storing more than a single bit of information, compared to a single-level cell (SLC), which can store only one bit per memory cell. A memory cell typically consists of a single floating-gate MOSFET, thus multi-level cells reduce the number of MOSFETs required to store the same amount of data as single-level cells.
The Opal Storage Specification is a set of specifications for features of data storage devices that enhance their security. For example, it defines a way of encrypting the stored data so that an unauthorized person who gains possession of the device cannot see the data. That is, it is a specification for self-encrypting drives (SED).
SandForce was an American fabless semiconductor company based in Milpitas, California, that designed flash memory controllers for solid-state drives (SSDs). On January 4, 2012, SandForce was acquired by LSI Corporation and became the Flash Components Division of LSI. LSI was subsequently acquired by Avago Technologies on May 6, 2014 and on the 29th of that same month Seagate Technology announced its intention to buy LSI's Flash Components Division.
NVM Express (NVMe) or Non-Volatile Memory Host Controller Interface Specification (NVMHCIS) is an open, logical-device interface specification for accessing a computer's non-volatile storage media usually attached via the PCI Express bus. The initial NVM stands for non-volatile memory, which is often NAND flash memory that comes in several physical form factors, including solid-state drives (SSDs), PCIe add-in cards, and M.2 cards, the successor to mSATA cards. NVM Express, as a logical-device interface, has been designed to capitalize on the low latency and internal parallelism of solid-state storage devices.
Kioxia Holdings Corporation, simply known as Kioxia and stylized as KIOXIA, is a Japanese multinational computer memory manufacturer headquartered in Tokyo, Japan. The company was spun off from the Toshiba conglomerate in June 2018 and gained its current name in October 2019; it is currently majority owned by Bain Capital which holds a 56% stake, while Toshiba holds a 41% stake.
