SSDs have been gaining ground for years now. Until recently, these flash-based storage devices have been mostly used by mobile devices, like smartphones or MP3 players. But more recently desktops and servers have been making use of this technology. What advantages do SSDs have over traditional storage devices? Find out here.Servers with SSD storage: a forward-thinking hosting strategy
SSDs are fast, quiet, and compact in size. Since they do not contain any mechanical components, they are considered more robust than classic HDDs in some cases. However, they are said to have a limited life span. Is that true? We'll explain how long SSDs last, how their life span can be extended, and which warning signals indicate an impending failure.
How long does an SSD last?
SSD technology is well developed today, even if there were premature failures during the initial period after flash memories were launched on the market. Sudden defects occur relatively rarely over the years, except during the first few weeks, when production errors might be noticeable ex works, for example. According to current failure statistics, SSDs are generally more reliable than classic HDDs in practice.
SSD vs. HDD: Other differences besides just service life also exist between the two storage technologies. SSD and HDD also differ from one another in terms of performance and, ultimately, price. Depending on the application scenario, you should therefore be sure to choose the right technology.
Nevertheless: The flash cells, which electronically store data onto an SSD device, have a clearly defined life span, in contrast to traditional magnetic storage devices. After a limited number of write-erase cycles, this becomes critical, since the flash memory of an SSD ages with every write process. Manufacturers usually state 1,000 to 100,000 write-and-erase operations.
The considerable range in the lifetime of an SSD is related to different storage technologies:
- Single-level cell SSDs (SLC) have a particularly long life, although they can only store 1 bit per memory cell. They can withstand up to 100,000 write cycles per cell and are particularly fast, durable, and fail-safe.
- Multi-level cell SSDs (MLC) have a higher storage density and can store 2 bits per flash cell. They are more cost-effective than the SLC type but can only tolerate up to 10,000 write cycles per cell.
- Triple-level cell SSDs (TLC) can hold 3 information bits per memory cell. However, at the same time, life expectancy can drop to 3,000 memory cycles per cell.
- Quad-level cell SSDs (QLC) accommodate 4 information bits per cell. Reduced costs, more storage capacity, and higher storage density are also associated with a shorter service life with this type of device. Manufacturers usually only guarantee 1,000 write or erase cycles per cell.
Although the range in SSD life spans is considerable, all SSD types have a sufficiently high life expectancy with moderate use (with some limitations, including for QLC SSDs).
The lifetime of an SSD device is customarily stated as a TBW value in the IT industry. TBW is an abbreviation for “total bytes written”, meaning the total number of bytes that can be written onto an SSD. Today, SSD manufacturers often state a service life (guaranteed write volume) of 256 TBW. With average PC usage, for example, around 80 TBW can be performed within 10 years. In the usage scenario “moderate, eight-hour, weekly use as an office PC” (word processing, surfing the net, checking emails, occasional streaming, a few larger downloads, as well as smaller backup and copying actions, but not a high continuous load), the hard drive would have a predicted life expectancy of approximately 32 years.
During long-term tests, which consistently write onto SSDs using special algorithms, it has also been revealed that manufacturers tend to rate an SSD life span rather conservatively. Even lower-cost SSDs easily exceed the manufacturer’s write limit.
The figures make it clear that the service life of an SSD with normal everyday use is hardly a limiting factor. An example SSD from Intel is still classified as completely intact by the HD Sentinel monitoring tool after almost 10 years of use (performance value: 100%, overall condition: 98%). A technical defect in the built-in electronics control system (controller) or an exchange due to insufficient storage capacity would be more likely than a failure.
Drive Writes Per Day (DWPD value)
However, if you record a large image backup on an SSD every day (e.g., 170 GB on a 180 GB disk), it can actually get tight after a few years. With a view to greater continuous use, a DWPDvalue is often given for SSDs: The manufacturer Kingston specifies a “Drive Writes Per Day” value of 0.30 for its DC400 DW SSD model (480 GB storage capacity). The value is calculated using a formula that includes the TBW value (Kingston adheres to a standardized calculation method based on JEDEC workload when determining the TBW value):
TBW of the SSD * 1000/365 days * Number of years * Storage capacity
In this specific example for calculating a DWPD value, the guarantee period of 5 years flows into the “number of years” (meaning the life span of an SSD that is guaranteed by the manufacturer):
257 * 1000/365 * 5 * 480
If the calculated DWPD value of 0.30 is multiplied by the storage capacity of the Kingston SSD (480 GB), the result is 144 GB. If you write a maximum of 144 GB to the SSD every day, it will most likely also reach the guaranteed life expectancy. For “Number of years”, instead of the guarantee period, you can also use a different number of years that corresponds to your requirements for an SSD in terms of service life and resilience.
What does the lifetime of an SSD depend on?
The values that are cited are not written in stone. The lifetime of SSDs significantly depends on the write strategy used. Manufacturers use special algorithms for this, which endeavor to achieve the most efficient “write management” possible. The widespread wear-leveling technology, which is managed by the built-in controller or the firmware of an SSD, evenly distributes the entries of all memory blocks. By not always writing in the same block, a balanced utilization and the subsequent delayed aging of an SSD can be achieved.
Another measure to extend the lifetime of an SSD is to activate the TRIM function. The TRIM command has provided improved memory management since Windows 7 was released. If the operating system was installed directly onto the SSD, it is usually activated automatically. You can also activate the command yourself via the command line (fsutil behavior set DisableDeleteNotify 0, if TRIM is deactivated). Activation is made easier with the tools that SSD manufacturers offer online for monitoring and maintaining solid state disks free of charge.
Over-provisioning is an optional component of intelligent storage management. If the function is activated, an operational “special memory” becomes available to the SSD controller. This can then be used as a kind of cache for managing and relocating temporary data. Over-provisioning can support SSD maintenance via garbage collection, wear leveling, and bad block management, for example. When the function is activated, however, you forego some storage capacity. Not all SSDs support this function.
As a user, you can also do something to increase the lifetime of the SSD. You can outsource backup directories for larger and write-intensive data backups to inexpensive HDDs. Folders for temporary files and browser profile folders, into which a lot of data is permanently written, do not have to be on an SSD. System-relevant files, which are also responsible for the performance of Windows (e.g., pagefile.sys, hiberfil.sys), should remain on the SSD in order to guarantee efficient system performance.
In addition to the most intelligent memory management possible, other factors are also decisive for the service life of the electronic memory. It is important to know how an SSD should be stored and handled. Thermal problems (e.g., high ambient temperatures) and high humidity can damage the memory or shorten its service life. Mechanical-physical influences (e.g., from falling) are less of a threat to an SSD than to a HDD, but damage from mechanical forces cannot be completely ruled out.
Electronic factors can also influence the lifetime of an SSD. The controller (meaning the control unit of an SSD) is particularly susceptible to surge damage. If SSDs are not used for a long time, data can also be lost if it is not accessed for a while. As a precaution, you should check on it occasionally, use it briefly, or at least boot the device. Otherwise, a loss of cell charge can lead to data degradation. Among other things, this can result in bit errors that, despite error correction, trigger firmware corruption and thereby disable an SSD. SSDs should therefore not be used for the permanent offline archiving of data.
Other factors include defective flash semiconductor memories, incorrectly programmed firmware and firmware updates, and memory management algorithms that have not been programmed optimally. SSDs are generally technologically complex. In terms of possible sources of error, malfunctions and negative influences that can end or at least limit service life, they are inferior to the simpler, classic, magnetic storage technology of HDDs. Of course, user errors and other factors can also lead to data loss, such as corrupt files, faulty file systems and file allocation tables, viruses, accidental formatting and the unplanned deletion of files, folders, and partitions.
Are there typical warning signs of imminent failure or damage?
Acoustic signals that could audibly indicate impending data loss do not occur with SSDs. In contrast to mechanically based HDDs, damaged SSDs do not click or clack. A defective controller, which often seals the fate of an SSD, is usually a silent and, unfortunately, immediate total loss.
However, if you use monitoring software such as SSD-Z or HD Sentinel, you can at least observe the degree of wear and tear of an SSD and keep an eye on the operating temperatures. Monitoring software that is available online and tools from SSD manufacturers often provide an overall assessment of the general condition of an SSD (this is mostly color-coded: green = very good, everything okay; red = caution, there are problems). Your assessment is usually based on the evaluation of SMART values (SMART = Self-Monitoring, Analysis, and Reporting Technology). This also includes the current TBW value and the power-on hours (or the entire previous operating time of an SSD). If the overall rating deteriorates significantly over the years, you should replace an SSD as a precaution.
In the event of an SSD problem, normal users can first check all connections. The SATA connection on a built-in SSD may have become loose, or the SATA connection on the mainboard may be defective. In the event of overheating problems, you can clean a dusty desktop PC from the inside, thereby restoring a functional cooling system.
Is it possible to restore data, and what does it cost?
In the event of a technical defect and the end of the SSD’s service life due to the write limit being reached, data recovery is virtually impossible or at least considerably more difficult to accomplish. Normal users can usually do very little in this respect. If you want to save your data, only one thing helps: quickly disconnecting the SSD from your computer, thereby preventing further changes to the SSD that are counterproductive to data recovery. You should then contact a professional data recovery service provider.
Since some controllers now also internally use encryption techniques from cryptography (integrated hardware encryption), an often-time-consuming decryption and reconstruction process follows. Only then can the recovered data bundle be made usable and readable again. In some cases, accidental deletion actions are almost impossible to undo with newer models or after executing TRIM commands. The chances of recovery are better in the event of a firmware problem, for example.
With regard to costs, it should be mentioned that these can vary considerably. Data recovery is usually much more expensive with SSDs than with conventional HDDs that use magnetic storage (if there is even any chance for success). Sometimes, simpler recovery actions can be completed after a few hours, but more complicated cases can take weeks and are correspondingly expensive. You should clarify the expected cost framework before commissioning the recovery company and, if necessary, get a cost estimate or a fixed price offer after an initial diagnosis has been made.
If the costs are too high for you, recovery software may also help. However, using such software may be counterproductive if you continue to work with the SSD and the algorithm-controlled autonomous storage organization becomes active again. In the event of electronic defects, further booting naturally also implies certain risks for successful data recovery. If you don’t have much knowhow about recovery, you can of course also make mistakes.
A securely encrypted cloud backup offers optimal protection for your data. Expensive downtimes and complicated data transfers to new hardware are things of the past with the flexible cloud backup solution from IONOS.
Better than any subsequent data recovery, especially when using complicated SSD technology, is preventive data backup, in which you systematically proceed according to the 3-2-1 rule. The most secure method is to use several distributed storage locations and data carriers, although you should also integrate a cloud and make use of its advantages. Professional cloud providers put your backup strategy on sound footing through automated data synchronization, mobile data access, redundant data backup, and encrypted data transfers.