3D NAND: “I Have More Layers than You Do!”

Layer CountYesterday’s news really underscored the race currently underway between 3D NAND makers to produce higher layer counts than one another.

Intel produced an announcement in which VP Rob Crooke bragged that: “Intel has delivered the world’s first commercially available 64-layer, TLC, 3D NAND solid state drive (SSD). While others have been talking about it, we have delivered.”

The announcement explained that the new Intel SSD 545s could be purchased at Newegg beginning that day.

The Memory Guy received Intel’s announcement at 10:02 AM Pacific Time.  By 3:11 PM, five hours later, there was another announcement in my “In” box, this time from Western Digital (WDC).

WDC’s e-mail announced the development of the the SanDisk/Toshiba next-generation BiCS4 3D NAND technology, with 96 layers.  The companies expect to begin to sample a 256Gb part to OEM customers in the second half of 2017 with production starting by the end of next year.

One has to wonder if WDC was Continue reading “3D NAND: “I Have More Layers than You Do!””

What is a “Multilayer Cell”?

MLCFrom time to time I get questions from investors in the memory business asking: “What is a multilayer cell?”

The answer is: “There is no such thing: It’s a misstatement.”

The term “MLC” has, by a number of people, been mistranslated to “multi-layer cell.”  The misunderstanding appears to have originated in the financial community.  People in the flash memory business never use the term at all.

Yes, we talk about MLC, but to us the term means “multilevel cell”.

A multilevel cell is a cell that uses varying voltage levels to represent different states.  With four voltage levels the resulting four states on a single cell can be turned into Continue reading “What is a “Multilayer Cell”?”