All Solid State Drives use NAND chips, however, SSDs from different Vendors are very different in performance and endurance, how does it happen?
Here are just some common methods Vendors use to avoid damaging flash cells and extend the life of
All Solid State Drives use NAND chips, however, SSDs from different Vendors are very different in performance and endurance, how does it happen?
Here are just some common methods Vendors use to avoid damaging flash cells and extend the life of the SSD drive. See SSD glossary if you see any term that you are not familar with.
The process of increasing the spare area on a solid-state drive. It increases the available “ready to be written” resource pool which decreases write amplification. Since there is less background data movement required, performance and endurance increases.
As an example, a drive with 100 GB usable capacity would have an extra 28 GB hidden capacity. The remaining capacity would be used for wear leveling.
SSD drives uses either static or dynamic wear leveling techniques, or both. Wear leveling allows for data to be mapped to different locations on the drive to avoid writing too often to the same cell.
SSD drives are equipped with sophisticated garbage collection technique. The "Garbage Collection Process" eliminates the need to perform erasure of the whole block prior to every write. It accumulates data marked for erase as "Garbage" and performs whole block erase as space reclamation in order to reuse the block, often doing this as a background process when the drive is not busy with I/O.
Data Buffering & caching:
Some SSD drives use DRAM for data buffer, caching to minimize write amplification ensuring the likelihood of damaging cells due to excessive writes.