If you didn’t know, we’re now able to offer Datakey RUGGEDrive™ with both Multi-Level Cell and Single-Level Cell NAND flash.
And now that we can do that, we’re getting asked more and more about the key differences between these two options.
So I thought I’d write a quick post about it!
Before I dive into MLC and SLC is it probably worth a reminder on flash memory itself.
Flash memory is made up of a large number of memory cells.
Each cell includes a floating gate field-effect transistor capable of holding a charge. The data in the cell in determined by whether there is a charge in the floating gate.
SLC has just one bit per cell, which can carry one of two different voltage levels, indicating that cell is either programmed or erased.
MLC typically has 2 bits per cell, which can therefore carry four different voltage levels. These indicate that the MLC cell can be fully programmed, partially programmed, partially erased or fully erased.
Most of us use MLC for portable flash storage, be it in a USB stick an SD card or Industrial memory products.
So why would you consider SLC?
SLC will give you faster read/write speeds, last longer than MLC and consume less power. The trade offs are that the cost per GB of memory is significantly more and generally memory capacities are lower.
To give you an example, the DFX-IS version of the RUGGEDrive™ which uses SLC NAND flash specifies 60,000 to 100,000 write cycles which is around 20 times more than the DFX version which uses MLC. The standard DFX is available in memory capacities from 4GB upwards while currently DFX-IS is only available with 1GB.
MLC is great for most industrial applications, however, if you have a particularly demanding industrial application, it could be worth considering SLC.
If you would like to know more about any of the Datakey RUGGEDrive™ products, just get in contact with us and as ever we will do our best to help you.