. Don’t Erase Data — This method is quick, but not secure. It removes the volume's catalog directory but leaves the actual data intact. Zero Out Data — This method provides a good level of security. It erases the volume's data by writing over it with zeros. The length of time this method takes depends on the size of the volume. 7-Pass Erase — This method meets the security requirements of the standards for erasing magnetic media.
Apr 12, 2014 i tried eraseing my internal hdd with disk utility to use it for secondary storage only, because i am booting osx mountain lion off a external ssd. So i dont need the osx on the internal hard drive anymore, id rather use it to store random files.But when i go in disk utilty to erase it.
This erase method can take a long time. 35-Pass Erase — This is the highest level of data erase security that Disk Utility supports. It writes over the data on a volume 35 times. Don't expect this erase method to finish any time soon. Fastest — This is the quickest erase method.
It doesn't scramble the file data, which means a recovery app may be able to resurrect the erased data. Zero Out the Data — This erase method writes a single path of zeros to all locations on the selected volume or disk. Advanced recovery techniques could restore the data, but it would require a great deal of time and effort. Three-Pass — This is a DOE-compliant three-pass secure erase. It writes two passes of random data to the volume or disk and then writes a single pass of a known data pattern to the volume or disk. Most Secure — This method of securely erasing a volume or disk meets the requirements of the U.S.
Department of Defense (DOD) 5220-22M standard for securely erasing magnetic media. The erased volume is written to seven times to ensure the data can't be restored. Select a drive from the list of drives and volumes shown in Disk Utility. Each drive in the list displays its capacity, manufacturer, and product name, such as 232.9 GB WDC WD2500JS-40NGB2. Click the Erase tab.
Enter a name for the drive. The default name is Untitled. The drive's name eventually, so it's a good idea to choose something that's descriptive, or at least more interesting than 'Untitled.' . Select a volume format to use. The Volume Format drop-down menu lists the available drive formats that the Mac supports.
Select Mac OS Extended (Journaled). Click Security Options to open a menu that displays multiple secure erase options. Optionally, select Zero Out Data. This option is for hard drives only and should not be used with SSDs. Zero Out Data performs a test on the hard drive as it writes zeros to the drive's platters. During the test, Disk Utility maps out any bad sections it finds on the drive's platters so they can't be used.
You won't be able to store any important data on a questionable section of the hard drive. The erase process can take a fair amount of time, depending on the drive's capacity. Make your selection and click OK to close the Security Options menu. Click the Erase button.
Disk Utility will unmount the volume from the desktop, erase it, and then remount it on the desktop. Insert the OS X Install DVD in your Mac's CD/DVD reader. Restart the Mac by selecting the Restart option in the Apple menu.
When the display goes blank, press and hold the c key on the keyboard. Booting from the DVD can take time. After you see the grey screen with the Apple logo in the middle, release the c key. Select Use English for the main language. When this option appears, and then click the arrow button.
Select Disk Utility from the Utilities menu. When Disk Utility launches, the drive from the disks and volumes listed at the left side of the Disk Utility window. Click the Erase tab. The selected drive's name and current format display in the right side of the Disk Utility workspace. Click Erase. Disk Utility unmounts the drive from the desktop, erases it, and then remounts it on the desktop.
512GB 960 PRO NVMe M.2 SSDA solid-state drive ( SSD) is a device that uses assemblies to store data, typically using, and functioning as in the. It is also sometimes called a solid-state device or a solid-state disk, although SSDs lack the physical spinning and movable used in ('HDD') or.Compared with the electromechanical drives, SSDs are typically more resistant to physical shock, run silently, and have quicker and lower. SSDs store data in cells. As of 2019, cells can contain between 1 and 4 of data. SSD storage devices vary in their properties according to the number of bits stored in each cell, with single bit cells ('SLC') being generally the most reliable, durable, fast, and expensive type, compared with 2 and 3 bit cells ('MLC' and 'TLC'), and finally quad bit cells ('QLC') being used for consumer devices that do not require such extreme properties and are the cheapest of the four. In addition, memory (sold by under the Optane brand), stores data by changing the electrical resistance of cells instead of storing electrical charges in cells, and SSDs made from can be used for high speed, when data persistence after power loss is not required, or may use battery power to retain data when its usual power source is unavailable.
Or (SSHDs), such as, combine features of SSDs and HDDs in the same unit using both and a HDD in order to improve the performance of frequently-accessed data.While the price of SSDs has continued to decline over time, SSDs are (as of 2020 ) still more expensive per unit of storage than HDDs and are expected to remain so into the next decade.SSDs based on will slowly leak charge over time if left for long periods without power. This causes worn-out drives (that have exceeded their endurance rating) to start losing data typically after one year (if stored at 30 °C) to two years (at 25 °C) in storage; for new drives it takes longer. Therefore, SSDs are not suitable for. Is a possible exception to this rule, however it is a relatively new technology with unknown data-retention characteristics.SSDs can use traditional interfaces and form factors, or newer interfaces and form factors that exploit specific advantages of the in SSDs.
Traditional interfaces (e.g., and ) and allow such SSDs to be used as drop-in replacements for HDDs in computers and other devices. Newer form factors such as, NF1, XFMEXPRESS and (formerly known as Ruler SSD ) and higher speed interfaces such as over can increase performance over HDD performance. Contents.Development and history Early SSDs using RAM and similar technology An early—if not the first—semiconductor storage device compatible with a hard drive interface (e.g.
An SSD as defined) was the 1978 STC 4305. The STC 4305, a plug-compatible replacement for the fixed head disk drive, initially used (CCDs) for storage and consequently was reported to be seven times faster than the product at about half the price ($400,000 for 45 MB capacity ). It later switched to. Before the StorageTek SSD there were many DRAM and core (e.g. Top and bottom views of a 2.5-inch 100 GB SATA 3.0 (6 Gbit/s) model of the Intel DC S3700 seriesEnterprise flash drives (EFDs) are designed for applications requiring high I/O performance , reliability, energy efficiency and, more recently, consistent performance. 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.
The term was first used by EMC in January 2008, to help them identify SSD manufacturers who would provide products meeting these higher standards. There are no standards bodies who control the definition of EFDs, so any SSD manufacturer may claim to produce EFDs when in fact the product may not actually meet any particular requirements.An example is the Intel DC S3700 series of drives, introduced in the fourth quarter of 2012, which focuses on achieving consistent performance, an area that had previously not received much attention but which Intel claimed was important for the enterprise market. In particular, Intel claims that, at a steady state, the S3700 drives would not vary their IOPS by more than 10–15%, and that 99.9% of all 4 KB random I/Os are serviced in less than 500 µs.Another example is the Toshiba PX02SS enterprise SSD series, announced in 2016, which is optimized for use in server and storage platforms requiring high endurance from write-intensive applications such as write caching, I/O acceleration and (OLTP). The PX02SS series uses 12 Gbit/s SAS interface, featuring MLC NAND flash memory and achieving random write speeds of up to 42,000 IOPS, random read speeds of up to 130,000 IOPS, and endurance rating of 30 drive writes per day (DWPD).SSDs based on 3D XPoint have higher random (higher IOPS) but lower sequential read-write speeds than their NAND-flash counterparts. They can have up to 2.5 million IOPS. Drives using other persistent memory technologies In 2017, the first products with memory were released under 's Optane brand.
3D Xpoint is entirely different from NAND flash and stores data using different principles.Architecture and function The key components of an SSD are the controller and the memory to store the data. The primary memory component in an SSD was traditionally, but since 2009 it is more commonly.
Controller Every SSD includes a that incorporates the electronics that bridge the NAND memory components to the host. The controller is an embedded processor that executes firmware-level code and is one of the most important factors of SSD performance. Some of the functions performed by the controller include:. mapping. via (ECC). and management.The performance of an SSD can scale with the number of parallel NAND flash chips used in the device.
A single NAND chip is relatively slow, due to the narrow (8/16 bit) interface, and additional high latency of basic I/O operations (typical for SLC NAND, 25 to fetch a 4 page from the array to the I/O buffer on a read, 250 μs to commit a 4 KB page from the IO buffer to the array on a write, 2 ms to erase a 256 KB block). 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.Micron and Intel initially made faster SSDs by implementing (similar to ) and in their architecture.
This enabled the creation of ultra-fast SSDs with 250 /s effective read/write speeds with the SATA 3 Gbit/s interface in 2009. Two years later, SandForce continued to leverage this parallel flash connectivity, releasing consumer-grade SATA 6 Gbit/s SSD controllers which supported 500 MB/s read/write speeds. SandForce controllers compress the data before sending it to the flash memory. This process may result in less writing and higher logical throughput, depending on the compressibility of the data.
Wear leveling. Main articles: andIf a particular block is programmed and erased repeatedly without writing to any other blocks, that block will wear out before all the other blocks — thereby prematurely ending the life of the SSD. For this reason, SSD controllers use a technique called to distribute writes as evenly as possible across all the flash blocks in the SSD.In a perfect scenario, this would enable every block to be written to its maximum life so they all fail at the same time. The process to evenly distribute writes requires data previously written and not changing (cold data) to be moved, so that data which are changing more frequently (hot data) can be written into those blocks. Each time data are relocated without being changed by the host system, this increases the and thus reduces the life of the flash memory. Designers seek to maximize both.
Memory Flash memory Comparison of architectures Comparison characteristics::Persistence ratio1: 101: 10Sequential write ratio1: 31: 4Sequential read ratio1: 11: 5Price ratio1: 1.31: 0.7Most SSD manufacturers use NAND in the construction of their SSDs because of the lower cost compared with and the ability to retain the data without a constant power supply, ensuring data persistence through sudden power outages. Flash memory SSDs were initially slower than DRAM solutions, and some early designs were even slower than HDDs after continued use. This problem was resolved by controllers that came out in 2009 and later.Flash-based SSDs store data in (MOS) chips which contain. Flash memory-based solutions are typically packaged in standard disk drive form factors (1.8-, 2.5-, and 3.5-inch), but also in smaller more compact form factors, such as the form factor, made possible by the small size of flash memory.Lower-priced drives usually use (TLC) or (MLC) flash memory, which is slower and less reliable than (SLC) flash memory. This can be mitigated or even reversed by the internal design structure of the SSD, such as interleaving, changes to writing algorithms, and higher (more excess capacity) with which the wear-leveling algorithms can work. See also: andSSDs based on volatile memory such as DRAM are characterized by very fast data access, generally less than 10, and are used primarily to accelerate applications that would otherwise be held back by the of flash SSDs or traditional HDDs.DRAM-based SSDs usually incorporate either an internal battery or an external AC/DC adapter and storage systems to ensure data persistence while no power is being supplied to the drive from external sources. If power is lost, the battery provides power while all information is copied from (RAM) to back-up storage.
This section's may be compromised due to out-of-date information. Please update this article to reflect recent events or newly available information. ( December 2018)Some SSDs, called or Hyper DIMM devices, use both DRAM and flash memory. When the power goes down, the SSD copies all the data from its DRAM to flash; when the power comes back up, the SSD copies all the data from its flash to its DRAM. In a somewhat similar way, some SSDs use form factors and buses actually designed for DIMM modules, while using only flash memory and making it appear as if it were DRAM. Such SSDs are usually known as devices.Drives known as or (SSHDs) use a hybrid of spinning disks and flash memory. Some SSDs use (MRAM) for storing data.
Cache or buffer A flash-based SSD typically uses a small amount of DRAM as a cache, similar to the in hard disk drives. A directory of block placement and wear leveling data is also kept in the while the drive is operating. One SSD controller manufacturer, does not use an external DRAM cache on their designs but still achieves high performance. Such an elimination of the external DRAM reduces the power consumption and enables further size reduction of SSDs. Battery or supercapacitor Another component in higher-performing SSDs is a capacitor or some form of battery, which are necessary to maintain data integrity so the data in the cache can be flushed to the drive when power is lost; some may even hold power long enough to maintain data in the cache until power is resumed.
In the case of MLC flash memory, a problem called lower page corruption can occur when MLC flash memory loses power while programming an upper page. The result is that data written previously and presumed safe can be corrupted if the memory is not supported by a supercapacitor in the event of a sudden power loss. This problem does not exist with SLC flash memory.Most consumer-class SSDs do not have built-in batteries or capacitors; among the exceptions are the Crucial M500 and MX100 series, the Intel 320 series, and the more expensive Intel 710 and 730 series. Enterprise-class SSDs, such as the Intel DC S3700 series, usually have built-in batteries or capacitors.Host interface. An SSD with 1.2 TB of MLC NAND, using PCI Express as the host interfaceThe host interface is physically a connector with the signalling managed by the. It is most often one of the interfaces found in HDDs.
They include:. (SAS-3, 12.0 Gbit/s) – generally found on. and mSATA variant (SATA 3.0, 6.0 Gbit/s). (PCIe 3.0 ×4, 31.5 Gbit/s).
(6.0 Gbit/s for SATA 3.0 logical device interface, 31.5 Gbit/s for PCIe 3.0 ×4). (PCIe 3.0 ×4). (128 Gbit/s) – almost exclusively found on servers. (10 Gbit/s). (UDMA, 1064 Mbit/s) – mostly replaced by SATA. (Parallel) ( 40 Mbit/s- 2560 Mbit/s) – generally found on servers, mostly replaced by; last SCSI-based SSD was introduced in 2004SSDs support various logical device interfaces, such as (AHCI) and (NVMe).
Logical device interfaces define the command sets used by to communicate with SSDs and (HBAs).Configurations The size and shape of any device is largely driven by the size and shape of the components used to make that device. Traditional HDDs and are designed around the rotating (s) or along with the inside. If an SSD is made up of various interconnected (ICs) and an interface connector, then its shape is no longer limited to the shape of rotating media drives. Some solid state storage solutions come in a larger chassis that may even be a rack-mount form factor with numerous SSDs inside. They would all connect to a common bus inside the chassis and connect outside the box with a single connector.For general computer use, the 2.5-inch form factor (typically found in laptops) is the most popular. For desktop computers with 3.5-inch hard disk drive slots, a simple adapter plate can be used to make such a drive fit.
Other types of form factors are more common in enterprise applications. An SSD can also be completely integrated in the other circuitry of the device, as in the (starting with the fall 2010 model).
As of 2014, and form factors also gained popularity, primarily in laptops.Standard HDD form factors. Main articles: andFor applications where space is at premium, like for ultrabooks or, a few compact form factors were standardized for flash-based SSDs.There is the mSATA form factor, which uses the physical layout. 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.form factor, formerly known as the Next Generation Form Factor (NGFF), is a natural transition from the mSATA and physical layout it used, to a more usable and more advanced form factor. 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.
The M.2 standard allows both SATA and SSDs to be fitted onto M.2 modules. Disk-on-a-module form factors. A 2 GB disk-on-a-module with PATA interfaceA disk-on-a-module ( DOM) is a flash drive with either 40/44-pin (PATA) or interface, intended to be plugged directly into the motherboard and used as a computer (HDD). 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, which are often deployed in harsh environments where mechanical HDDs would simply fail, or in because of small size, low power consumption and silent operation.As of 2016, storage capacities range from 4 MB to 128 GB with different variations in physical layouts, including vertical or horizontal orientation.Box form factors Many of the DRAM-based solutions use a box that is often designed to fit in a rack-mount system. The number of DRAM components required to get sufficient capacity to store the data along with the backup power supplies requires a larger space than traditional HDD form factors. Bare-board form factors.
A custom-connector SATA SSDForm factors which were more common to memory modules are now being used by SSDs to take advantage of their flexibility in laying out the components. Some of these include, and many more. The SATADIMM from Viking Technology uses an empty DDR3 DIMM slot on the motherboard to provide power to the SSD with a separate SATA connector to provide the data connection back to the computer.
The result is an easy-to-install SSD with a capacity equal to drives that typically take a full 2.5-inch. At least one manufacturer, has produced a drive that sits directly on the SATA connector (SATADOM) on the motherboard without any need for a power cable. Some SSDs are based on the PCIe form factor and connect both the data interface and power through the PCIe connector to the host. These drives can use either direct PCIe flash controllers or a PCIe-to-SATA bridge device which then connects to SATA flash controllers. Ball grid array form factors In the early 2000s, a few companies introduced SSDs in (BGA) form factors, such as M-Systems' (now ) DiskOnChip and 's NANDrive (now produced by ), and 's M1000 for use in embedded systems.
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 directly onto a system motherboard to reduce adverse effects from vibration and shock.Such embedded drives often adhere to the and standards.Comparison with other technologies Hard disk drives. See also:Making a comparison between SSDs and ordinary (spinning) HDDs is difficult. Traditional HDD tend to focus on the performance characteristics that are poor with HDDs, such as. As SSDs do not need to spin or seek to locate data, they may prove vastly superior to HDDs in such tests. However, SSDs have challenges with mixed reads and writes, and their performance may degrade over time. SSD testing must start from the (in use) full drive, as the new and empty (fresh, out-of-the-box) drive may have much better write performance than it would show after only weeks of use.Most of the advantages of solid-state drives over traditional hard drives are due to their ability to access data completely electronically instead of electromechanically, resulting in superior transfer speeds and mechanical ruggedness.
On the other hand, hard disk drives offer significantly higher capacity for their price.Some field failure rates indicate that SSDs are significantly more reliable than HDDs but others do not. However, SSDs are uniquely sensitive to sudden power interruption, resulting in aborted writes or even cases of the complete loss of the drive.
The reliability of both HDDs and SSDs varies greatly among models.As with HDDs, there is a tradeoff between cost and performance of different SSDs. Single-level cell (SLC) SSDs, while significantly more expensive than multi-level (MLC) SSDs, offer a significant speed advantage. At the same time, DRAM-based solid-state storage is currently considered the fastest and most costly, with average response times of 10 microseconds instead of the average 100 microseconds of other SSDs. Enterprise flash devices (EFDs) are designed to handle the demands of tier-1 application with performance and response times similar to less-expensive SSDs.In traditional HDDs, a re-written file will generally occupy the same location on the disk surface as the original file, whereas in SSDs the new copy will often be written to different NAND cells for the purpose of.
The wear-leveling algorithms are complex and difficult to test exhaustively; as a result, one major cause of data loss in SSDs is firmware bugs.The following table shows a detailed overview of the advantages and disadvantages of both technologies. CompactFlash card used as an SSDWhile both and most SSDs use flash memory, they serve very different markets and purposes. Each has a number of different attributes which are optimized and adjusted to best meet the needs of particular users. Some of these characteristics include power consumption, performance, size, and reliability.SSDs were originally designed for use in a computer system. The first units were intended to replace or augment hard disk drives, so the operating system recognized them as a hard drive.
Originally, solid state drives were even shaped and mounted in the computer like hard drives. Later SSDs became smaller and more compact, eventually developing their own unique form factors such as the form factor. The SSD was designed to be installed permanently inside a computer.In contrast, memory cards (such as (SD), (CF), and many others) were originally designed for digital cameras and later found their way into cell phones, gaming devices, GPS units, etc. Most memory cards are physically smaller than SSDs, and designed to be inserted and removed repeatedly. There are adapters which enable some memory cards to interface to a computer, allowing use as an SSD, but they are not intended to be the primary storage device in the computer.
The typical card interface is three to four times slower than an SSD. 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.SSD failure SSDs have very different than traditional magnetic hard drives. Because of their design, some kinds of failure are inapplicable (motors or magnetic heads cannot fail, because they are not needed in an SSD). Instead, other kinds of failure are possible (for example, incomplete or failed writes due to sudden power failure can be more of a problem than with HDDs, and if a chip fails then all the data on it is lost, a scenario not applicable to magnetic drives). However, on the whole statistics show that SSDs are generally highly reliable, and often continue working far beyond the expected lifetime as stated by their manufacturer. SSD reliability and failure modes An early test by which ran for 18 months during 2013 - 2015 had previously tested a number of SSDs to destruction to identify how and at what point they failed; the test found that 'All of the drives surpassed their official endurance specifications by writing hundreds of terabytes without issue', described as being far beyond any usual size for a 'typical consumer'. The first SSD to fail was a TLC based drive - a type of design expected to be less durable than either SLC or MLC - and the SSD concerned managed to write over 800,000 GB (800 TB or 0.8 ) before failing; three SSDs in the test managed to write almost three times that amount (almost 2.5 PB) before they also failed.
Main article:Typically the same used on hard disk drives can also be used on solid state drives. It is usually expected for the file system to support the which helps the SSD to recycle discarded data (support for TRIM arrived some years after SSDs themselves but is now nearly universal). This means that file system does not need to manage or other flash memory characteristics, as they are handled internally by the SSD. Some flash file systems using designs (, ) help to reduce write amplification on SSDs, especially in situations where only very small amounts of data are changed, such as when updating.While not a file system feature, operating systems should also aim to correctly, which avoids excessive cycles.
A typical practice for personal computers is to have each partition aligned to start at a 1 (= 1,048,576 bytes) mark, which covers all common SSD page and block size scenarios, as it is divisible by all commonly used sizes - 1 MB, 512 KB, 128 KB, 4 KB, and 512 bytes. Modern operating system installation software and disk tools handle this automatically.Linux The, and file systems include support for the discard (TRIM or UNMAP) function.Kernel support for the TRIM operation was introduced in version 2.6.33 of the Linux kernel mainline, released on 24 February 2010. To make use of it, a file system must be mounted using the discard parameter. Linux partitions are by default performing discard operations when the underlying drive supports TRIM, with the possibility to turn them off, or to select between one-time or continuous discard operations. Support for queued TRIM, which is a feature that results in TRIM commands not disrupting the command queues, was introduced in Linux kernel 3.12, released on November 2, 2013.An alternative to the kernel-level TRIM operation is to use a user-space utility called fstrim that goes through all of the unused blocks in a filesystem and dispatches TRIM commands for those areas.
Fstrim utility is usually run by as a scheduled task. As of November 2013, it is used by the, in which it is enabled only for Intel and Samsung solid-state drives for reliability reasons; vendor check can be disabled by editing file /etc/cron.weekly/fstrim using instructions contained within the file itself.Since 2010, standard Linux drive utilities have taken care of appropriate partition alignment by default. Linux performance considerations. An SSD that uses as the logical device interface, in form of a ×4During installation, usually do not configure the installed system to use TRIM and thus the file requires manual modifications. This is because of the notion that the current Linux TRIM command implementation might not be optimal. It has been proven to cause a performance degradation instead of a performance increase under certain circumstances.
As of January 2014, Linux sends an individual TRIM command to each sector, instead of a vectorized list defining a TRIM range as recommended by the TRIM specification. This deficiency has existed for years and there are no known plans to eliminate it.For performance reasons, it is recommended to switch the I/O scheduler from the default (Completely Fair Queuing) to. CFQ was designed for traditional magnetic media and seek optimizations, thus many of those I/O scheduling efforts are wasted when used with SSDs.
As part of their designs, SSDs offer much bigger levels of parallelism for I/O operations, so it is preferable to leave scheduling decisions to their internal logic – especially for high-end SSDs.A scalable block layer for high-performance SSD storage, known as blk-multiqueue or blk-mq and developed primarily by engineers, was merged into the in kernel version 3.13, released on 19 January 2014. This leverages the performance offered by SSDs and, by allowing much higher I/O submission rates. With this new design of the Linux kernel block layer, internal queues are split into two levels (per-CPU and hardware-submission queues), thus removing bottlenecks and allowing much higher levels of I/O parallelization. As of version 4.0 of the Linux kernel, released on 12 April 2015, block driver, the layer (which is used by Serial ATA drivers), framework, driver, (UBI) driver (which implements erase block management layer for flash memory devices) and driver (which exports RADOS objects as block devices) have been modified to actually use this new interface; other drivers will be ported in the following releases. MacOS Versions since Mac OS X 10.6.8 (Snow Leopard) support TRIM but only when used with an Apple-purchased SSD. TRIM is not automatically enabled for third-party drives, although it can be enabled by using third-party utilities such as Trim Enabler.
The status of TRIM can be checked in the System Information application or in the systemprofiler command-line tool.Versions since OS X 10.10.4 (Yosemite) include sudo trimforce enable as a Terminal command that enables TRIM on non-Apple SSDs. There is also a technique to enable TRIM in versions earlier than Mac OS X 10.6.8, although it remains uncertain whether TRIM is actually utilized properly in those cases. Microsoft Windows Versions of Microsoft Windows before 7 do not take any special measures to support solid state drives. Starting from Windows 7, the standard NTFS file system provides TRIM support (other file systems on Windows do not support TRIM ).By default, Windows 7 and newer versions execute TRIM commands automatically if the device is detected to be a solid-state drive. To change this behavior, in the key HKEYLOCALMACHINESYSTEMCurrentControlSetControlFileSystem the value DisableDeleteNotification can be set to 1 to prevent the mass storage driver from issuing the TRIM command.
This can be useful in situations where data recovery is preferred over wear leveling (in most cases, TRIM irreversibly resets all freed space).Windows implements TRIM command for more than just file delete operations. The TRIM operation is fully integrated with partition- and volume-level commands like format and delete, with file system commands relating to truncate and compression, and with the System Restore (also known as Volume Snapshot) feature. Windows 7 Windows 7 and later versions have native support for SSDs. The operating system detects the presence of an SSD and optimizes operation accordingly. For SSD devices Windows disables and, boot-time and application prefetching operations. Despite the initial statement by Steven Sinofsky before the release of Windows 7, however, defragmentation is not disabled, even though its behavior on SSDs differs. One reason is the low performance of on fragmented SSDs.
The second reason is to avoid reaching the practical maximum number of file fragments that a volume can handle. If this maximum is reached, subsequent attempts to write to the drive will fail with an error message.Windows 7 also includes support for the TRIM command to reduce garbage collection for data which the operating system has already determined is no longer valid.
Without support for TRIM, the SSD would be unaware of this data being invalid and would unnecessarily continue to rewrite it during garbage collection causing further wear on the SSD. It is beneficial to make some changes that prevent SSDs from being treated more like HDDs, for example cancelling defragmentation, not filling them to more than about 75% of capacity, not storing frequently written-to files such as log and temporary files on them if a hard drive is available, and enabling the TRIM process.
Windows 8.1 Windows 8.1 and later Windows systems like Windows 10 also support automatic TRIM for PCI Express SSDs based on. For Windows 7, the KB2990941 update is required for this functionality and needs to be integrated into Windows Setup using DISM if Windows 7 has to be installed on the NVMe SSD. Windows 8/8.1 also support the SCSI unmap command for USB-attached SSDs or SATA-to-USB enclosures. SCSI Unmap is a full analog of the SATA TRIM command. It is also supported over Protocol (UASP).The graphical Windows Disk Defagmenter in Windows 8.1 also recognizes SSDs distinctly from hard disk drives in a separate Media Type column. While Windows 7 supported automatic TRIM for internal SATA SSDs, Windows 8.1 and Windows 10 support manual TRIM (via an 'Optimize' function in Disk Defragmenter) as well as automatic TRIM for SATA, NVMe and USB-attached SSDs.Windows Vista generally expects hard disk drives rather than SSDs.
Includes to exploit characteristics of USB-connected flash devices, but for SSDs it only improves the default partition alignment to prevent read-modify-write operations that reduce the speed of SSDs. Most SSDs are typically split into 4 kB sectors, while most systems are based on 512 byte sectors with their default partition setups unaligned to the 4 KB boundaries. The proper alignment 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.Drive should be disabled because the location of the file components on an SSD doesn't significantly impact its performance, but moving the files to make them using the Windows Defrag routine will cause unnecessary write wear on the limited number of P/E cycles on the SSD. The feature will not materially improve the performance of the system and causes additional overhead in the system and SSD, although it does not cause wear. Windows Vista does not send the TRIM command to solid state drives, but some third part utilities such as SSD Doctor will periodically scan the drive and TRIM the appropriate entries. ZFS as of version 10 Update 6 (released in October 2008), and recent versions of, with, and all can use SSDs as a performance booster for. A low-latency SSD can be used for the ZFS Intent Log (ZIL), where it is named the SLOG.
This is used every time a synchronous write to the drive occurs. An SSD (not necessarily with a low-latency) may also be used for the level 2 (L2ARC), which is used to cache data for reading. When used either alone or in combination, large increases in performance are generally seen.
FreeBSD ZFS for FreeBSD introduced support for TRIM on September 23, 2012. The code builds a map of regions of data that were freed; on every write the code consults the map and eventually removes ranges that were freed before, but are now overwritten. There is a low-priority thread that TRIMs ranges when the time comes.Also the (UFS) supports the command. Swap partitions. According to Microsoft's former Windows division president, 'there are few files better than the pagefile to place on an SSD'. According to collected data, Microsoft had found the to be an ideal match for SSD storage. partitions are by default performing operations when the underlying supports TRIM, with the possibility to turn them off, or to select between one-time or continuous TRIM operations.
If an operating system does not support using TRIM on discrete partitions, it might be possible to use swap files inside an ordinary file system instead. For example, OS X does not support swap partitions; it only swaps to files within a file system, so it can use TRIM when, for example, swap files are deleted.
allows SSD-configured swap to also be used as file system cache. This can be used to boost performance on both desktop and server workloads. The, and projects provide a similar concept for the Linux kernel.Standardization organizations The following are noted standardization organizations and bodies that work to create standards for solid-state drives (and other computer storage devices). The table below also includes organizations which promote the use of solid-state drives. Main article:In general, performance of any particular device can vary significantly in different operating conditions. For example, the number of parallel threads accessing the storage device, the I/O block size, and the amount of free space remaining can all dramatically change the performance (i.e. Transfer rates) of the device.SSD technology has been developing rapidly.
Most of the performance measurements used on disk drives with rotating media are also used on SSDs. Performance of flash-based SSDs is difficult to benchmark because of the wide range of possible conditions.
In a test performed in 2010 by Xssist, using, 4 kB random 70% read/30% write, queue depth 4, the IOPS delivered by the Intel X25-E 64 GB G1 started around 10,000 IOPs, and dropped sharply after 8 minutes to 4,000 IOPS, and continued to decrease gradually for the next 42 minutes. IOPS vary between 3,000 and 4,000 from around 50 minutes onwards for the rest of the 8+ hour test run.is the major reason for the change in performance of an SSD over time.
Designers of enterprise-grade drives try to avoid this performance variation by increasing, and by employing wear-leveling algorithms that move data only when the drives are not heavily utilized. This section needs to be updated. Please update this article to reflect recent events or newly available information. ( April 2018)SSD shipments were 11 million units in 2009, 17.3 million units in 2011 for a total of US$5 billion, 39 million units in 2012, and were expected to rise to 83 million units in 2013to 201.4 million units in 2016 and to 227 million units in 2017.Revenues for the SSD market (including low-cost PC solutions) worldwide totalled $585 million in 2008, rising over 100% from $259 million in 2007. See also.References. This article's use of may not follow Wikipedia's policies or guidelines.
Please by removing or external links, and converting useful links where appropriate into. ( February 2020) Background and general.
long term SSD reliability review. French a 2012 update of a 2010 report based on data from a leading French tech retailer., SSD Form Factor Work Group, December 12, 2012Other. (PDF). (USENIX 2013, by Mai Zheng, Joseph Tucek, Feng Qin and Mark Lillibridge)., FrugalGaming, by James Heinfield.