Endurance

• As we said, each FLASH cell can sustain up to 100,000 program/erase cycles.
• This makes the life of an SSD very short under heavy write load.
• To alleviate this - the SSD controller employs "write-leveling" techniques.
  • It counts how many times each page was programmed.
  • When a write arrives, it chooses a block of pages that were least written into.
  • This way, all cells will have performed approximately the same number of program/erase cycles, at any given time.

Originally written by guy keren