Nowadays, no one buys a computer, whether desktop or laptop, that does not have a USB flash drive as its main storage unit. SSD. Despite all their benefits and great capabilities, they present several problems that must be taken into account. One of the main problems comes with the bad blockssomething that can cause loss of information and that can occur in these cases.
SSD drives are divided into blocks or cells, which wear out and eventually become damaged. This is a normal process, with all drives having extra cells to fill these spaces that have been irreparably damaged.
There are two situations that can cause damaged blocks or cells. The first situation is during the manufacturing process of the memory chips. In addition, these can be damaged during normal use of the storage unit.
Situations that can irreparably damage SSD cells
All SSDs on the market have a bad block table (BBT). This is a ‘black list’ of all the cells or blocks that are not working properly. It saves their position and thus avoids sending information there that could be lost.
Before performing a writing process, this BBT list is consulted, to avoid saving information in them. The aim is to ensure the security of the user’s data.
The list is stored in a separate fail-safe section. The controller is tasked with storing a backup copy of the list, in case it needs to be restored in the event of an incident.
Since the problem of block wear is known, manufacturers “add” a reserved amount of memory. This additional amount of memory is reserved exclusively to replace damaged cells. The controller is aware of the damaged cell and enables a new cell, copying the stored information to prevent it from being lost.
You should know that there are two situations that can damage a block or accelerate its degradation. The first is to suffer blows or strong vibrations. While these units have no moving parts and are more resistant to these circumstances, they are not immune. If the fall is large or the vibration is extreme, it could damage part or all of the unit.
An event that can accelerate the wear of the unit is, curiously, the little space in the unit of storage. Something that seems harmless can put stress on the SSD and cause damage to the cells. This is not particularly common, but you should take it into consideration.
Please note that the number of replaceable blocks is finite. Once the limit is reached, the cells will not be “regenerated” so to speak, and we are not heading for degradation of the drive. Under reasonable, “normal” use of the drive, problems may take up to a decade to appear.
Symptoms of drive degradation are quite evident. We will notice that the operating system takes longer to load than normal and transfer times increase. We may also experience problems loading files or excessive delays in application startup times.
In the event of any of these events or just in case, we should make a backup. Then we can use tools like SSD Fresh to check the health status of the SSD. If it indicates that there is a risk or a problem, we should simply change the storage unit.