What is a NAND Flash Memory?

Electronically speaking, a flash memory cell can be a NAND or a NOR gate. As stated in secondary school physics, a NAND gate (NOT-AND) is a logic gate (electronic circuit) that produces a false output (0) only if all its inputs are 1 (True). NAND has many advantages over NOR, so most flash memory cells are NAND. A flash memory device consists internally of large arrays of MOSFET transistors configured as NAND gates. NAND is a non-volatile flash memory cell that retains its data in the absence of power.

  • In the 3D process, memory cells are stacked vertically on top of each layer like a multi-story building.
  • In 2D or planner arrangement, cells are side by side.

3D NAND or V NAND (Vertical) Technology

There is confusion between NAND and 3D NAND. 3D is a manufacturing technique to stack layers of memory cells on top of each other and connecting each layer of NAND cells with pillars, like a multi-story building or skyscraper. 3D NAND may have any of NAND types as a building block like SLC, MLC, TLC. 

Advantages of 3D NAND over 2D or Planner NAND

Manufacturing flash memory cells in 3D has many advantages over 2D planner technology. In legacy 2D or planner technology, manufacturers must reduce the size of a flash memory cell to increase the density to make a higher-capacity device. Reducing cell size has many disadvantages like cross-interference and latency-related issues. Over the years, manufacturers have been in a race to reduce cell size. Started 120 nm, the current cell size is 14nm. More reduction in cell size is difficult in available technologies. More cells must fit in the same space for higher capacity drives. There is no such limit in 3D. Layers of memory cells are stacked vertically in 3D. Manufacturers have the option to increase the cell size for better performance, latency, and high endurance. Today, most high-capacity SSDs have 3D or V-NAND technology, cells stacked vertically.

Game-Changing Solution in High Capacity SSDs 

Vertical stacking of cells dramatically increases the storage capacity. To increase the drive size, No need to shrink the cells unnecessarily. Cells have the required size and enough inter cells space to reduce cross-interference. 3D technology boosts performance, increases endurance, and reduces latency. A typical 1TB SSD may consist of 64 of such stacked layers. Announced in December 2020, Intel has built SSDs around the industry’s first 144-layer NAND. NAND is a storage technology for flash storage devices. 3D or Vertical (V-NAND) is a technology to stack cells in multiple layers to increase cell density, reduce cost, increase storage capacity, and improve performance.

Why We Need 3D NAND SSDs?

As of 2021, the flash memory market has reached $57 billion in sales. 3D NAND is the only option for SSDs to reach terabytes capacities. It provides a faster performance along with higher endurance, low power consumption, and economy.

Types of NAND Flash

Currently, at the time of writing, SLC, MLC, TLC, QLC, and PLC are five flash memory cells types. The difference between each NAND type is the number of bits each cell can store. SLC can hold 1 BIT and has the highest performance and endurance, whereas PLC has five bits with low endurance and performance.

Single-Level Cell (SLC) (1 Bit per Cell)

SLC or Single Level Cell stores 1 bit of information per cell. The SLC stores either a 0 or 1 (1 Bit). It is the fastest, reliable, but most expensive. SLC type is the first choice for high-end servers and mission-critical applications. 100,000 P/E cycles.

Multi-Level Cell (MLC) (2 Bits per Cell)

Multi-Level cells can store 2 bits per cell. MLC has a good combination of price, performance, and endurance. 10,000 P/E cycles

Triple-Level Cell (TLC) (3 Bits per Cell)

TLC or Triple Level Cell can store 3 bits of data per cell. It is the most common technology found in mainstream consumer high-capacity SSDs. It is a cheap option with low endurance compare with SLC and MLC. 3000 P/E cycles.

Quad-Level Cell (QLC) (4 Bits per Cell)

Quad level Cell or QLC cell can store 4 bits of data. QLC is the answer for the cheaper high capacity consumer SSDs. 1000 P/E cycles. Samsung has QLC SSDs called the QVO series.  

Penta Level Cell (PLC) (5 Bits per Cell)

Penta level cell, each cell stores 5 bits. Slowest performance, low endurance but the cheapest.


NAND and NOR are logical gates (electronic circuits). Most flash memory devices have NAND memory cells as a building block.

3D NAND can be an SLC, MLC, TLC, QLC, or PLC. SLC type flash memory is the most expensive, whereas 3D TLC NAND is the most common type in the consumer SSD market.

What is the best type of NAND?

SLC or Single Level cell is better while connected as 3D SLC NAND is the best.

What is the difference between 2D and 3D NAND?

2D NAND or planner flash memory chip has side-by-side arranged memory cells. More cells must be packed into the same space to increase the memory capacity. Available technology has limits to reduce cell size. In 3D, layers of flash memory cells are stacked vertically (also called V-NAND) on top of each layer. It provides a performance boost along with higher endurance, low power consumption, and it is economical.

SLC, MLC, TLC, QLC, and PLC – Which SSD Should I Buy For PC?

The best of both worlds for price and performance is 3D MLC or 3D TLC, TLC being the cheaper option. It is economical and has better performance & endurance (5 years warranty). You get what you pay. Besides NAND type, also look for the TBW or Terabytes written. TBW is a value in Terrabytes you can write to the SSD over the life span of the SSD.

What is TLC NAND?

It is a triple-level cell, and each cell can store 3 bits. It is the most common type found in mainstream consumer high-capacity SSDs called 3D TLC NAND. Samsung EVO and WD Blue series are 3D TLC NAND.

What is 3D TLC NAND?

TLC memory cells connected in 3D. It is the most common SSD type in the consumer market.

Which is better? TLC or 3D NAND

TLC is a type of flash memory cell. 3D is a technology to connect memory cells in stacked layers on top of each other. So an SSD can be a 3D TLC NAND.


3D or V-NAND is a technology, and TLC, MLC is a building block of flash memory cells. So an SSD can be a 3D-MLC-NAND or 3D-TLC-NAND.

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