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I want to buy a SSD, but I am confused as to how 3D NAND (that is now the latest and greatest) relate to MLC, TLC and QLC ?

Is there like 3D NAND TLC or 3D NAND QLC ? Or this 3D NAND completely separate from these ?

ng.newbie
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1 Answers1

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3D NAND refers to the layout of the chip's memory cells, while MLC, TLC and QLC refer to technology of each cell.

For example, the NAND flash in Intel’s SSD D5-P4326 is referred to as 3D QLC. QLC, or quad-level cell technology, refers to each memory cell’s ability to save four bits of data across 15 different threshold voltages. 3D is a reference to the way memory cells are built.

Previously, cells were arranged side by side on a silicon substrate. As their density increased with new lithography processes, more of them could fit on a planar surface. But as it became increasingly difficult to scale along the x- and y-axis, manufacturers started organizing them vertically along the z-axis.

Taking as an example a 64 layers-tall flash device, 3D NAND enables here 64 times the cell density of planar memory. When adding QLC technology, that 64x is turned into 256x. That way, Intel’s 64-layer 3D NAND used in the SSD D5-P4326 can fit 1Tb density per die, for a higher-capacity SSD in the same form factor.

harrymc
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