There are two types of NAND Flash available in USB flash drives - SLC (Single Level Cell) and MLC (Multi Level Cell).

• SLC flash accesses and writes to the flash faster, by using "simpler" control logic with 1 bit vs. the 2 bits used by MLC flash.
• The program operations in SLC chips last 100,000 cycles, ten times longer than MLC.
• At a first glance, SLC flash appears to be more expensive than MLC. However, taking into consideration the higher reliability and lifespan of SLC, the aggregate cost is for SLC is lower.

If performance and durability are essential for your system, SLC Flash is the solution. If low cost and high density are essential, MLC Flash is the right choice.