This is a major problem for storage vendors that simply aggregate SSDs together in an array. This drop in performance is known as the Write Cliff. Once their drive starts the process of garbage collection they suddenly have to wait. The result of this is often seen by SSD users who experience amazing performance when the drive is new, but soon see a noticeable drop in performance. If users try to write data to an SSD that is in the process of garbage collection, their writes will have to wait for the entire erase process to finish. When they are in the process of garbage collection they cannot write any new data. Solid State Drives (SSDs) operate in the same way. They must first erase what is on the page and then they can write something new. A person cannot both erase a page in a notebook and simultaneously write new data to that same page.

With flash storage the process of erasing old data and making space available is known as garbage collection. Erasing data on a block of cells is much like erasing an entire page in a notebook. People write on a page and then move on to the next page. Flash writes to and erases groups of cells known as blocks.

People to do not write and erase individual letters on a page and, similarly, flash does not write and erase individual cells. It also takes time to perform this action, which reduces overall performance. Similarly, flash memory erases used space by over-writing what is already there, which consumes one of the limited number of writes that cell can have and reduces its usable life. Also, it takes more time to erase the spot before writing to it than it would to simply write to an empty space. Writing-erasing-writing to the same spot multiple times means the paper will eventually wear out. LetвЂ™s return to our pencil and paper analogy. Once data is written to a cell, that cell cannot be written to again unless the data that is already there is erased. Once a single letter or number is written to a given spot on a piece of paper, that particular space cannot be legibly written to again, unless what is written there is erased first. Using a paper and pencil is truly the traditional way to store data.

Here is a simple explanation on how data is stored in flash and how flash wears out using the analogy of a pencil and paper. Thus, the useful life of the flash storage depends upon how often data is written to it. While there is no predetermined number of times a cell can be read from, there is a limit to the number of times that data can be written to a given cell. In contrast, while flash memory has no moving parts to wear out, it still has limitations on its usable life.ДЇlash storage is made up of cells and, within a given cell, an electrical charge can be used to write data, which can then be read later. The reason for this is that they have moving parts that will eventually wear out and the drive will stop working. It is well understood that traditional hard disk drives fail.

Flash drive empty but space used