Can you compare SLC vs. MLC flash memory chips? How are they different?
Single-level cell (SLC) flash memory stores one bit per cell and multi-level cell (MLC) flash memory stores more than one bit per cell. The most common form of MLC stores two bits per cell and is sometimes known as MLC-2. Three-bit per cell is known as MLC-3 or triple-level cell (TLC) and four-bit per cell is known as MLC-4. Each bit has two states, 0 and 1, and there are different voltage levels to achieve these states.
SLC is relatively simple because with only one bit per cell, each cell can only have two states. As bits are added per cell, more states are required per cell. MLC-2 has four states, MLC-3 has eight states, and MLC-4 has 16 states. Each of these states requires discrete voltage levels to achieve, which has an effect on the performance for that type of flash, decreasing the write throughput as more bits per cell are added.
This was first published in January 2012