How Much the Difference Between SLC and MLC SD?


At present, the flash memory applications on the market are mainly USB digital camera and other memory cards, mainly using MLC type (multi-level cell) SD and SLC type (single-level cell) NAND flash memory particles. There is no difference in appearance, but in actual use, the difference between different NAND flash memory particle types is still obvious.

First, let us introduce:

What is SLC or MLC SD Card?

There are two different types of industrial NAND flash memory. One is called SLC (Single Level Cell), single-level cell flash memory. There are only two potential storage states of 0 and 1; the other is called MLC (Multi Level Cell), multi-level cell flash memory.

MLC SD can store two bits of information into a Floating Gate at a time. The Floating Gate is the part of the flash memory used to store charges. Through different charge quantities, MLC can present 4 different storage states, each state represents two binary digital values (00, 01, 10, and 11). It is called Multi Level Cell because of this feature.
Because the manufacturing process of MLC is relatively difficult, the yield rate is not easy to improve, but the manufacturing cost of NAND Flash using MLC process can be lower than that of SLC process.

The main difference between the two is that each cell of SLC stores one bit of data, while MLC uses a large number of voltage levels, and each cell stores two bits of data, and the data density is relatively large.


MLC SD Versus SLC Performance

In terms of performance, SLC should be superior to MLC. MLC-type NAND flash memory particles adopt multi-layer cell technology, represented by Japanese manufacturer Toshiba, which mainly adopts 0.13 micron manufacturing process.

Compared with SLC, MLC using multi-layer cell technology Flash memory chips have higher storage density and more competitive prices. However, MLC SD has a slower reading and writing speed and higher energy consumption than SLC. Under the same conditions of use, it consumes about 15% more current than SLC, so the service life is shorter, and the number of stable accesses is generally about 10,000.

MLC SD Advantage

The advantage of MLC-type flash memory chips lies in its cost, which can easily increase the storage density of products without additional investment in production equipment.

The SLC single-layer cell technology was launched by Samsung, a Korean manufacturer, mainly using a 0.9-micron manufacturing process. At present, a higher 0.6-micron product has been launched. The single-layer cell technology has a cell access time of 25 us, which is also in terms of energy consumption. It is lower than MLC and uses 1.8V more voltage. The use of SLC flash memory chips in these mobile products can improve the energy-saving requirements of mobile devices, and at the same time extend the service life, and can guarantee about 100,000 stable accesses.

However, Dellwa provide 100% of the SLC SD cards have been tested in Taiwan, ranging from 8GB to 128GB.

MLC SLC SSD Difference

The storage density of MLC relative to SLC must be higher, so the cost is also lower, but the disadvantage that the speed is slower. On the other hand, the lifespan of SLC is 100,000 writes, while MLC is 10,000.

Although MLC has a significant advantage over SLC in terms of price, the lifespan of SLC is about ten times that of MLC.

In recent years, benefiting from multi-channel reading and writing technology. As long as an excellent control chip is used, MLC can also have good reading and writing speed and longevity. Therefore, under the price advantage, if choose a reliable brand or supplier, I believe that MLC can also perform satisfactorily.

Dellwa MLC SSD

Kingston Brand SSD


MLC flash memory is used to reduce the cost of flash memory card products, and is common in most low-speed cards.

SLC flash memory is used in high-performance flash memory cards, and is only used by some high-end flash card manufacturers. Provide higher read and write speeds, lower energy consumption, more stable performance, and longer service life. In general, slc chips meet high-end industrial equipment like SSD which have higher quality and performance requirements for products. And MLC SD meets USB and memory cards which demand economical product prices.


From Dellwa sales manager Alan Tsai said:
“The application field of memory card in bulk and memory card bulk purchase are about automotive, telecom, GPS, embedded, recorder and displays, medical and healthcare, etc.
We are mlc micro sd card suppliers wholesale glad to provide you memory cards for suitable you are significant and sophisticated equipment. “
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