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SSD [Edit] - Wikipedia, the free encyclopedia (Redirected from �SSD�) The current version is not tested and experienced participants may differ significantly from the version screened January 8, 2013, checks require 12 edits. Query �SSD� redirects here, see also other meanings.
SSD 2.5 "and a pencil Tverdotelny drive (born SSD, solid-state drive) - a non-mechanical computer storage device based on memory chips. Besides them, SSD contains master controller. There are two types of solid-state drives: SSD-based memory such as RAM and SSD based on flash memory. Currently, solid-state drives are used in compact devices: laptops, netbooks, smartphones and communicators, but they can also be used in the system unit to improve performance. Some well-known manufacturers have switched to the production of solid-state drives are already full, for example Samsung has sold the business of manufacturing hard drives of Seagate. There are also so-called hybrid hard disks, appeared, including because of the current is proportional to the higher cost of SSDs. These devices combine in one device a hard disk drive (HDD) and solid state drive a relatively small amount, as the cache (to improve performance and product life, low energy consumption). While these drives are mainly used in mobile devices (laptops, mobile phones, tablets and the like).
Contents
1 History 2 Architecture and operation 2.1 NAND SSD 2.2 RAM SSD 3 advantages and disadvantages 3.1 Disadvantages 3.2 Advantages 4 Microsoft Windows computers and the platform with solid state drives 5 Mac OS X and Mac computers with solid state drives 6 Prospects 7 See also 8 Notes 9 Links
The history of
1978 - U.S. company StorageTek developed the first solid state drive of the modern type (based on the RAM-memory.) 1982 - U.S. company Cray introduced a semiconductor storage device for RAM-memory for its supercomputers Cray-1 at a rate of 100 Mbit / s and the Cray X-MP at 320 Mbit / s, with 8, 16 or 32 million 64-bit words. 1995 - Israeli company M-Systems introduced the first solid state drive to flash-memory. 2008 - The South Korean company Mtron Storage Technology managed to create a SSD drive with a write speed 240 MB / s and read speeds of 260 MB / s, which she demonstrated at the exhibition in Seoul. The scope of the drive - 128 GB. According to the company, the production of such devices was appointed in 2009. 2009 - Super Talent Technology has released a 512 GB SSD. , OCZ SSD is 1TB. Currently, the most prominent companies that actively develop SSD-direction in their work include Intel, Kingston, Samsung Electronics, SanDisk, Corsair, Renice, OCZ Technology, Crucial and ADATA. In addition, his interest in this market demonstrates Toshiba. Architecture and functioning
NAND SSD
Comparison: the disassembled components HDD (left) and analyzed SSD (right) Drives built on the use of non-volatile memory (NAND SSD), appeared recently [when?], But due to the much lower cost (from $ 1 per gigabyte) started confidently conquer the market. Until recently, much as the traditional storage devices - hard drives - in the writing speed, but made up for it's high-speed information retrieval (initial position). It is now available in solid-state drives with read and write speeds, many times greater than the possibility of hard drive. Characterized by its relatively small size and low power consumption.
RAM SSD
These drives are built on the use of volatile memory (the same as used in the PC RAM) are characterized by super-fast read, write, and search for information. Their main disadvantage is the extremely high cost. Are mainly used in order to accelerate large data base management systems and high-end graphics stations. These drives are usually equipped with a battery to store data when power is lost, and the more expensive models - backup systems and / or operational software. An example of these drives is I-RAM. Users with sufficient memory, can do a virtual machine and place it the hard disk into RAM and assess performance. Advantages and disadvantages
Limitations
The main drawback of NAND SSD - a limited number of write cycles. Normal (MLC, Multi-level cell, multi-level memory cell) flash memory allows you to record data about 10,000 times. More expensive types of memory (SLC, Single-level cell, single-level cell memory) - more than 100,000 times. [8] In order to combat uneven wear used load balancing schemes. The controller keeps track of the number of times which blocks overwritten and the need to "change their places". This is not a lack of RAM SSD. Subproblems compatible SSD drives with outdated and even many current versions of the OS family of Microsoft Windows, which does not take into account the specifics of SSD drives, and additionally they wear out. Using the operating system swapping mechanism (swap) to the SSD as well, with high probability, reduces the life of the drive; Price gigabyte SSD-drives substantially higher prices gigabyte HDD. In addition, the cost of SSD directly proportional to their capacity, while the cost of traditional hard disk drives depend on the number of plates and slowly increases with the size of a drive. Application in the SSD-drives TRIM command prevents recovery of deleted information recovery-utilities. Inability to recover information at a differential voltage. Since the controller and the media in the SSD are on the same board, when exceeded, or voltage drop often burns the entire SSD media to irretrievable loss of information. In contrast, hard drives often burns only the controller board, which makes it possible to recover the information with reasonable complexity. In general, if there was a hardware failure SSD because of a failure of the controller chip and flash memory, it makes the process of data recovery is almost impossible.
Advantages No moving parts, hence: No noise; High mechanical resistance; Stability of time reading files regardless of their location or fragmentation, and moreover, the sectors consecutive terms of operating system, because of wear leveling (wear leveling) will be placed in random order. High read / write speed, often exceeding the capacity of the hard disk interface (SAS / SATA II 3 Gb / s, SAS / SATA III 6 Gb / s, SCSI, Fibre Channel, etc.), and an even higher rate of non-linear reading / recording on the hard disk; IOPS up of tens to thousands of times than the hard drive. Low power consumption; Wide operating temperature range; Great modernization potential, as they themselves drive and the technology of their production; The absence of a magnetic disk from here: Much less sensitive to electromagnetic fields; Small size and weight (no need to do a heavy body for screening). Microsoft Windows computers and the platform with solid state drives
In Windows 7, introduced a special optimization for use with solid state drives. In the presence of SSD-drives this operating system treats them differently than conventional HDD-drives. For example, Windows 7 does not apply to the SSD-drive defragmentation, Superfetch and ReadyBoost technology and other techniques prefetching to speed application loading with conventional HDD-ROM drive. Previous versions of Microsoft Windows a special optimization do not have and are designed to work only with regular hard drives. So, for example, some file operations Windows Vista, without being disconnected, can reduce the life of SSD-drive. Defragmentation operation must be disabled, as it had virtually no impact on performance SSD-only media, and additional wear on him. ASUS is still in 2007 released a netbook EEE PC 701 with SSD-drive capacity of 4GB. Dell is September 9, 2011 stated that the first to market complete notebook Dell Precision Solid State Drive 512Gb volume single drive and two 1TB drives for the computer models M4600 and M6600, respectively. Manufacturer has determined the price for one 512Gb SATA3 drive at the time the $ 1120 in U.S. dollars. [10] SSD-drive to work tablet by Acer - Iconia Tab W500 model and W501, Fujitsu Stylistic Q550 Windows 7.
Mac OS X and Mac computers with solid state drives
Operating system Mac OS X from version 10.7 (Lion) fully implements support for the TRIM-installed in the system of solid state memory. Since 2010, Apple introduced computers line Air, fully staffed only on the basis of solid-state memory-NAND flash memory. Until 2010, the buyer can choose the computer hard drive in a normal configuration, but further development of the series in favor of the maximum relief and reducing computer housings of the series required a complete rejection of conventional hard drives in favor of solid state drives. The volume of completed with memory in computers Air series is from 64GB up to 512Gb. According to JP Morgan, after the submission has been sold 420,000 computers in this series is completely solid-state flash-NAND memory. June 11, 2012 based on flash memory was introduced a new 15-inch MacBook Retina, which optionally can be installed 768 GB of flash memory. Prospects of development
The main disadvantage of SSD drives - a limited number of write cycles - with the development of technology of manufacturing non-volatile memory will be eliminated by making the other physical principles and other materials, for example, FeRam. By 2014, HP plans to launch in retail stores, built on technology ReRAM (resistive random-access memory).
