November 4, 2009, 7:55 am
In our last article, we did a deep-dive on the anatomy of SSDs, starting with the basics of the NAND Flash cells that are floating-gate transistors. The transistors are then combined to form pages, which are formed into blocks, which are formed into planes, which are formed into chips, which are formed into drives. As discusssed, floating-gate transistors have a few limitations:
- Very fast read performance
Asymmetric read/write performance (reads are 2-3 orders of magnitude faster than writes)
There are data retention limitations due to leakage and due to exercising the cells (i.e. using the erase/program cycles)...