What is an SSD? How does this technology work?
What does SSD actually mean? These are the acronyms of a hard disk technology that stands out for its sophistication and speed. Although the precursors of SSD drives appeared as early as the fifties, it is from 1970 onwards when we talk about SSD storage. Previous solutions were extremely expensive, had minimal durability and without power supply lost content (volatile data storage).
It wasn’t till the 1990s the initial flash memory-based SSD that stored stored information without determined by the energy source and was a non-volatile memory could get to the marketplace. Along with flash modules, SDRAM storage modules are employed (chiefly as cache memory through usage ) which, though volatile, will also be substantially quicker than traditional RAM memories. Now’s industrial SSDs reach a storage capability of around 100 terabytes with 5 million write cycles and a statistics preservation warranty of up to ten decades. They’re used such as in servers with rapid SSDs.
What does SSD mean?
The expression strong state means semiconductor parts , that’s, we talk of a device made from semiconductor components. Thus, an SSD driveway is a group of several semiconductor components which are utilized by an electronic data file management program. FAT32 and NTFS file systems may be used to arrange information within an SSD driveway, which we describe in different posts.
How does this technology work?
In an SSD drive, information is written in semiconductor cells . These cells maintain their state even if there is no power supply (the principle of flash memory ). A memory cell has only two states: loaded or unloaded. This method is called Single Level Cell (SLC) and is used mostly in very expensive industrial SSD drives. Since one cell equals one bit, it is clear how many such cells are needed to reach one gigabyte (1 GB): 10 9 = 1 billion memory cells (exact value: 2 30= 1 073 741 824). A single letter in ASCII code already requires eight bits, so you can already imagine how much storage space is required for a text or image document.
However, it is also possible to increase the storage density of each cell so that it can store more than 1 bit. This type of storage is called Multi Level Cell (MLC) and allows 2 bits per cell. This reduces physical storage space and, with it, costs. The disadvantage is the lower number of write cycles. Another type of storage is the Triple Level Cell (TLC), with which manufacturing costs decrease again.
Semiconductors have limited durability . To counteract this, SSDs have an internal controller that detects worn memory cells. The so-called Bad Block Management marks as erroneous the cell blocks whose cells show risk of failure and replaces them with cells from a reserve . Depending on the SSD model, this reserve represents between 2 and 7% of the total storage capacity and increases the durability of an SSD considerably.
Nor can we forget the type of hybrid hard drive (known as HHD), which combines features of HDD hard drives and SSD drives. The fast flash memory of the SSD can increase the overall speed of the hybrid over a normal HDD. However, it falls short of competing with the rare SSDs.
Main advantages and disadvantages of an SSD drive compared to conventional HDD models
But where there are lights, there are also shadows, although in this case the shadows of the SSDs are acceptable.
Main advantages of SSD drives
A remarkable advantage of SSD drives is the speed of access to data: we are talking about approximately one hundredth of the time required by HDD hard drives. Added to this is a higher reading and writing data transfer speed . An SSD drive does not require boot time nor does it have mechanical components (except for the connectors). In addition, this technology is shock resistant, does not vibrate and, thanks to its low energy demand, does not overheat. The volume-storage space ratio is also more economical. Also, the quiet operation of an SSD drive is a significant advantage for many users.
Disadvantages of this technology
SSD hard drives are (still) considerably more expensive than conventional hard drives and their number of read and write cycles is limited due to the characteristics of the semiconductors used. Solid state drives are also especially sensitive to high temperatures.
You will find more information about the advantages and disadvantages of conventional hard drives and SSD drives in our article SSD vs. HDD . To learn more about Shingled Magnetic Recording technology, which allows you to increase the storage density in magnetic devices, do not miss our article on the SMR .
What tasks are SSD drives recommended for?
More and more devices are equipped with SSD drives in the commercial field , whether they are laptops, computers, digital cameras or music players. It is already common for computers to use SSD drives as system disks for the operating system and programs, while HDD hard drives (often with more capacity) are used to store work data. The smartphones and tabletsThey generally have a shorter lifespan than fixed devices, which is why these types of mobile devices are predestined to use SSD drives. All these teams benefit from the properties of an SSD drive: lightness, speed and resistance to shocks. The downward trend in the price of SSD drives suggests that all storage solutions in the consumer sector will be equipped with SSD drives in the future.
Furthermore, this storage technology is used when it is necessary to have large amounts of information in (near) real time , such as in the aeronautics and space sector (e.g. in flight data recorders) but also in military contexts.