Flash Chip Type (TLC, MLC, SLC)

When deciding what type of flash to use for an application, it is important to understand the differences between flash technologies. The following document explains the pros and cons of the three types of flash, SLC, MLC and TLC.

SLC- Single Layer Cell

• High performance
• Lower power consumption
• Faster write speeds
• 100,000 program/erase cycles per cell
• Higher cost
• A good fit for industrial grade devices, embedded systems, critical applications.

MLC- Multi Layer Cell

• Lower endurance limit than SLC
• 10,000 program/erase cycles per cell
• Lower cost
• A good fit for consumer products. Not suggested for applications which require frequent update of data.

TLC- Three Layer Cell

• Higher density
• Lower endurance limit than MLC and SLC
• TLC has slower read and write speeds than conventional MLC
• 5,000 program/erase cycles per cell
• Best price point
• A good fit for low-end basic products. Not suggested for critical or important applications at this time which require frequent updating of data.

SLC vs. MLC vs. TLC as explained with a glass of water

This glass of water analogy demonstrates how SLC NAND Flash outperforms MLC NAND Flash.

• SLC Flash has only two states: erased (empty) or programmed (full).
• MLC Flash has four states: erased (empty), 1/3, 2/3, and programmed (full).
• TLC Flash has eight states: erased (empty), 1/7, 2/7, 3/7, 4/7, 5/7, 6/7 and programmed (full).

It’s easier to read the correct fill status when a glass is either empty or full, as in SLC NAND Flash. When a glass is partially full, as in MLC NAND Flash, the fill status is more difficult to read, taking more time and energy.

Durability & Reliability

The program and erase operations of SLC NAND Flash last 100,000 cycles - ten times longer than MLC NAND Flash, whose program and erase operations only last 10,000 cycles. After 10,000 cycles, the reliability of MLC NAND Flash’s program and erase operations is not guaranteed.