WHAT ARE SSD SOLID STATE HARD DRIVES?

Dell began shipping ultra-portable laptops with SanDisk SSDs on April 26, 20[117] Asus released the Eee PC subnotebook on October 16, 2007, with 2, 4 or 8 gigabytes of flash memory.Defragmentation negatively affects the life of the SSD and has no benefit.14] 1987 saw the entry of EMC Corporation (EMC) into the SSD market, with drives introduced for the mini-computer market.112] Vista does not natively implement TRIM command, either.DragonFly BSD As a unique feature, DragonFly BSD allows SSD-configured swap to also be used as file system cache.In 1995, M-Systems introduced flash-based solid-state drives.If a software encryption program encrypts data already on the SSD, the overwritten data is still unsecured, unencrypted, and accessible (drive-based hardware encryption does not have this problem).The interface is generally one of the interfaces found in HDDs.The term was first used by EMC in January 2008, to help them identify SSD manufacturers who would provide products meeting these higher standards.70] Generally high since the mechanical components require additional time to get aligned Data transfer rate SSD technology can deliver rather consistent read/write speed, but when lots of individual smaller blocks are accessed, performance is reduced.SSDs do not employ any moving mechanical components, which distinguishes them from traditional magnetic disks such as hard disk drives (HDDs) or floppy disks, which are electromechanical devices containing spinning disks and movable read/write heads.102] Mac OS X Mac OS X 7 (Lion) supports TRIM, as does OS X 8 Snow Leopard.126] In November 2010, Fusion-io released its highest performing SSD drive named ioDrive Octal utilising PCI-Express x16 Gen 0 interface with storage space of 12 TB, read speed of 0 GB/s, write speed of 4 GB/s and a low latency of 30 microseconds.60] Comparison of SSD with hard disk drives SSD benchmark, showing about 230 MB/s reading speed, 210 MB/s writing speed and about 1 ms seek time, all independent from the accessed disk location.Higher performing SSDs have similar read and write speeds.Listed below are some notable computer file systems which are optimized for solid-states drives.Applications Until 2009, SSDs were mainly used in those aspects of mission critical applications where the speed of the storage system needed to be as fast as possible.Swap partitions On Linux, swap partitions automatically exploit TRIM operations when the underlying drive supports TRIM (no configuration is needed).They would all connect to a common bus inside the chassis and connect outside the box with a single connector.Usually no exposed circuitry.This problem does not exist with SLC flash memory.111] The proper alignment really does not help the SSD's endurance over the life of the drive, however some Vista operations, if not disabled, can shorten the life of the SSD.SSD technology uses electronic interfaces compatible with traditional block input/output (I/O) hard disk drives.This problem was resolved by controllers that came out in 2009 and later.High altitude operation Can endure high altitude during operation.Since flash memory has become a common component of SSDs, the falling prices and increased densities have made it more financially attractive for many other applications.For desktop computers with 5" hard disk slots, a simple adapter plate can be used to make such disk fit.The Apple Store cost was $999 more for this option, as compared with that of an 80 GB 4200 RPM hard disk drive.ZFS Solaris as of version 10 Update 6 (released in October 2008), and recent versions of OpenSolaris, Solaris Express Community Edition, Illumos, Linux with ZFS on Linux and FreeBSD all can use SSDs as a performance booster for ZFS.The strategy the drive operates by internally can largely vary between manufacturers and, the TRIM command zeroes the whole range of a deleted file.May need a few milliseconds to come out of an automatic power-saving mode.Data transfer rate depends also upon rotational speed, which can range from 4,200 to 15,000 rpm.But with the introduction of cheaper drum storage units, their use was discontinued.Partitions can be manually aligned before OS installation.When multiple NAND devices operate in parallel inside an SSD, the bandwidth scales, and the high latencies can be hidden, as long as enough outstanding operations are pending and the load is evenly distributed between devices.To remedy this issue, swap files inside an ordinary file system may be used.4][49] These traditional form factors are known by the size of the rotating media, e.2] The prices have continued to decline in 20[3] SSDs share the I/O interface technology developed for hard disk drives, thus permitting simple replacement for most applications.Most of recent models work well in all orientations.9] In 1976 Dataram started selling a product called Bulk Core, which provided up to 2 MB of solid state storage compatible with Digital Equipment Corporation (DEC) and Data General (DG) computers.The package included a rechargeable battery to preserve the memory chip contents when the array was not powered.In most cases, an EFD is an SSD with a higher set of specifications, compared with SSDs that would typically be used in notebook computers.19] Since then, SSDs have been used successfully as HDD replacements by the military and aerospace industries, as well as for other mission-critical applications.Some of these include PCIe, mini PCIe, mini-DIMM, MO-297, and many more.DRAM-based SSDs usually incorporate either an internal battery or an external AC/DC adapter and backup storage systems to ensure data persistence while no power is being supplied to the drive from external sources.HDDs can fail in this way too, but often give warning that they are failing, allowing much or all of their data to be recovered.HDDs have moving parts, and are subject to potential mechanical failures from the resulting wear and tear.114][115] On some operating systems[which?Once the head is positioned, when reading or writing a continuous track, an enterprise HDD can transfer data at about 140 MB/s.

Likewise, there may be other SSD manufacturers that meet the EFD requirements without being called EFDs.It also includes support for the TRIM command to reduce garbage collection for data which the operating system has already determined is no longer valid.Along with the emerging enterprise market, SSDs have been appearing in ultra-mobile PCs and a few lightweight laptop systems, adding significantly to the price of the laptop, depending on the capacity, form factor and transfer speeds.SNIA N/A Develops and promotes standards, technologies, and educational services in the management of information SSSI SNIA Fosters the growth and success of solid state storage Commercialization Cost and capacity The technological trend of 50% decline in costs per year is no longer possible in NAND flash due to patents on some key manufacturing processes stifling further competition in the market.Solid-state drive From Wikipedia, the free encyclopedia (Redirected from Ssd) Jump to: navigation, search This article is about flash-based, DRAM-based, and other solid-state storage.As memory cards are not designed to tolerate the amount of reading and writing which occurs during typical computer use, their data may get damaged unless special procedures are taken to reduce the wear on the card to a minimum.Eliminating the external DRAM enables a smaller footprint for the other flash memory components in order to build even smaller SSDs.While not a file system feature, operating systems must also align partitions correctly to avoid excessive read-modify-write cycles.Controller Every SSD includes a controller that incorporates the electronics that bridge the NAND memory components to the host computer.21] In 2007, Fusion-io announced a PCIe-based SSD with 100,000 input/output operations per second (IOPS) of performance in a single card, with capacities up to 320 gigabytes.128] Also announced was the Z-Drive R5 which is available in capacities up to 12 TB capable of reaching transfer speeds of 16 GB/s and 52 million IOPS using the PCI Express x16 Gen 0[129] Quality and performance Main article: Disk drive performance characteristics SSD technology has been developing rapidly.If power is lost, the battery provides power while all information is copied from random access memory (RAM) to back-up storage.Secure writing limitations NAND flash memory cannot be overwritten, but has to be rewritten to previously erased blocks.Free block availability and TRIM SSD write performance is significantly impacted by the availability of free, programmable blocks.The 20 MB unit could be used instead of a hard drive.66] Traditional hard drives store their data in a linear, ordered manner.Combined with a cloud computing environment or other writable medium, to maintain persistence, an OS booted from a write-locked SD card is robust, rugged, reliable, and impervious to permanent corruption.The interface is usually incorporated into the controller discussed above.Cirrus Logic's flash controller operation, allowing the company to enter the flash memory business for consumer electronic devices.Memory Flash memory-based Most[citation needed] SSD manufacturers use non-volatile NAND flash memory in the construction of their SSDs because of the lower cost compared with DRAM and the ability to retain the data without a constant power supply, ensuring data persistence through sudden power outages.It achieved a maximum write speed of 654 megabytes per second (MB/s) and maximum read speed of 712 MB/s.HDDs are definitely either upgradeable, changeable, or downgradable.11] The following year, StorageTek developed the first modern type of solid-state drive.Flash memory SSDs are slower than DRAM solutions, and some early designs were even slower than HDDs after continued use.Traditional HDD benchmarks are focused on finding the performance aspects where they are weak, such as rotational latency time and seek time.