Help, who can help me? I am choosing hardware components for a new computer and intend to choose between SSD and RAM. I’ve heard of NAND flash and DRAM, but I don’t know much about the difference. So, who can tell me what is NAND flash memory or types of NAND flash memory? Is NAND flash better than DRAM? How long does NAND storage last?
NAND flash memory is a non-volatile storage technology that does not require power to retain data. It is widely used in various electronic devices such as solid-state drives (SSDs), USB drives, memory cards, and smartphones.
You might be curious about how NAND flash memory works. Well, NAND flash stores and reads data using electricity. Each memory cell is like a small box that can hold an electric charge. If the box has a charge, it represents “0”. If it doesn’t, it is “1”. So, when you write data, you’re either putting a charge into or removing it from these boxes. When you read data, the system checks whether or not there’s a charge in the box.
Types of NAND flash memory:
SLC (Single-Level Cell): It is an old-fashioned NAND flash memory, which is fast and durable but expensive and has a lower storage density.
MLC (Multi-Level Cell): Each cell in MLC stores two bits of data, but this results in lower endurance compared with SLCs, as write cycles and erasures occur twice as often.
TLC (Triple-Level Cell): Each cell stores three bits of data, providing even higher density at lower cost, but with slower speeds and reduced endurance.
QLC (Quad-Level Cell): Each Quad-level unit can represent up to 4 bits, maximizing storage capacity but requiring further trade-offs in terms of speed and durability.
NAND and DRAM are the two most common types of semiconductor chips on the market. NAND is a non-volatile memory, while DRAM is a volatile memory. Each has advantages and disadvantages. Therefore, you can compare them according to actual scenarios and requirements. Here are the main differences:
Architecture: In NAND and DRAM memory, the greater the number of cells, the greater the storage capacity. Each DRAM unit stores one bit (0 or 1), which is simple in structure but needs to be refreshed periodically.
NAND, on the other hand, can store multiple bits per cell. For example, SLC (single-layer unit) stores 1 bit, and MLC (multi-layer unit) stores 2 bits. This multi-bit storage increases storage density but decreases speed and durability.
Speed: DRAM is much faster than NAND, making it ideal for applications that require quick data access, such as real-time operations in computer memory. In contrast, NAND is slower, which can be a limitation for applications that need fast data processing. However, NAND offers a larger storage capacity and can permanently store data on its chips.
Cost: NAND is typically cheaper per gigabyte than DRAM, making it a cost-effective solution for high-capacity storage needs. DRAM has a higher price per GB, but it is suitable for applications that require high-speed memory because of its speed and performance.
Use Cases: NAND is suitable for long-term storage, such as SSDs, USB drives, and other devices that need to retain data without power.
DRAM is suited for temporary storage, where quick access to data is critical, such as computer memory for active processes and applications.
The lifespan of NAND flash memory is influenced by many factors like write/erase cycles and data retention capabilities. Different types of NAND, such as SLC, MLC, TLC, and QLC, offer varying levels of durability, with SLC being the most durable and QLC the least. Additionally, factors like operating conditions, temperature, and the effectiveness of wear-leveling algorithms can impact overall longevity.