MLC SSD and SLC SSD

We have had some posts which were about SSD. Hope you could find helpful information for your SSD purchasing.

We also have talked about SSD related information such as interface types SATA I, II, III, which are one of factor which affect SSD’s data transfer performance. Today let’s talk about the SSD’s storage memory types.

What are there SSD flash memory types ?

Normally, we think there are 2 main SSD flash memory types: MLC and SLC.

MLC: Multi Level Cell NAND flash memory.

SLC: Single Level Cell NAND flash memory.

What different is between MLC and SLC ?

Current major SSD products use NAND Flash memory as storage units. NAND (negative-AND) is type of digital electronic logic gate compared to another type Nor gate.

MLC flash use multiple levels in a single cell to store more data compared to single level (SLC) in single cell using same number of transistors. Since the cost of SSD is based on unit of storage (ie: per MB of storage), so using same units, such as 250 GB storage, the MLC SSD will be cheaper than SLC SSD;

However, SLC memory has the advantage of faster writing speeds and longer cell life time. so actually SLC SSD has higher performance, also, the price is more expensive than MLC.

What SSDs are MLC type ? What SSDs are SLC type ?

In current SSD market, if you buy a 500 GB using around 200 CAD, the SSD should be MLC type, such as Samsung 850 EVO 500 GB.

But if you use 200 CAD to by a SLC SSD, you might only get a 32 GB size.

 

Of course the prices are based on current SSD market, we do not know exactly that the future of MLC and SLC, some people said MLC will replace SLC completely, but since SLC’s outstanding better performance, nobody can predict the future correctly.