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When will TLC flash come to enterprise storage arrays?

Triple-level cell (TLC) flash is designed to overcome one of the key problems with flash storage: capacity.

It seems likely triple-level cell (TLC) flash will begin making its way into enterprise environments in late 2015 or 2016.

TLC flash is designed to overcome the flash storage issue of capacity. Most flash drives are currently based on multi-level cell flash, which allows each cell to store two bits of data. The problem is that a finite number of cells can be physically placed into a die. If a flash manufacturer wants to increase capacity, it has three options:

  • Increase the physical size of the die
  • Shrink the size of the cell
  • Adopt a new cell architecture

Increasing the size of the die and decreasing the size of the cell both have issues. Flash memory cells eventually wear out as a result of undergoing too many write operations. Larger cells are more durable than smaller ones, and are therefore able to sustain a greater number of writes. Also, the number of electrons that can exist within a cell decreases as the cell shrinks. There eventually comes a point when a cell's small size translates directly to less reliability due to factors such as electron leakage (electrons jumping from cell to cell).

So, flash manufacturers are moving toward the only other option: a new cell architecture. TLC cells will increase flash capacity by adding a bit of storage to each cell. It is only a matter of time before TLC becomes widely adopted for enterprise storage.

But even TLC flash has its limits when it comes to storage capacity. TLC flash may eventually be overtaken by 3-D NAND flash, which seeks to increase capacity by adding vertical layers to the die.

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