Solidigm, the NAND research and manufacturing division sold by Intel to Kioxia, will attend the Flash Memory Summit 2022, Showcasing a completed working SSD prototype featuring the company’s latest NAND technology: Penta Level Cell (PLC). PLC builds on NAND density by adding the ability to store up to 5 bits of data in a single cell (up from QLC with 4 bits per cell), increasing the amount of space available in each NAND Flash chip. Increase quantity.
This new technology therefore paves the way for even cheaper $/GB ratios in PLC-based SSDs than is currently possible with Quad Level Cell (QLC) technology (most (enterprise, data center, and other critical environments). Despite the alarming pace of growth in the amount of data that humans generate (By 2025, 463 exabytes of data are projected to be created per day), storage technology must also evolve to accommodate this avalanche. With increasing investment in supercomputing and the dawn of 5G and AI, both with their own deep data storage requirements, Solidigm sees his PLCs as a cost-effective way to scale.
We believe the benefits of QLC and PLC #NAND will grow to meet the data-intensive needs of AI, machine learning, big data analytics, and support 5G. We are energized for the future and we are doing our best to seize this moment. #TheNewParadigm #FMS2022 #SSD https://t.co/184jvKPGDE pic.twitter.com/AsKWjYujOTAugust 8, 2022
PLCs work by adding additional voltage states that represent bits of information within a cell. Whereas the SLC had to handle only two voltage states (whether the bit was written or not), the MLC doubled that number to four voltage states (so each cell has a 0 and a 1 can include any combination of both). PLC NAND technology requires 32 different voltage states to distinguish between all possible combinations of 1s and 0s that a cell can hold. This puts additional strain on the cell and controller level, increasing the chances of incorrectly written voltage states and corrupted data. Therefore, stronger error correction algorithms should be implemented at the controller level.
Each additional bit per cell requires doubling the voltage state, which has its own impact on the life expectancy of the cell, and requires much more to cope with the ever-smaller difference between states. Requires fine-tuned read and write capabilities. As the bit storage capacity increases, the life expectancy of NAND cells decreases, which is commonly believed to make QLC SSDs less reliable (cells “die” sooner) than those with fewer bits. It’s part of the reason I’m here.
The law of diminishing returns is very clear when scaling NAND density by additional bits per cell. Essentially, each additional bit of information in a single NAND cell increases the required voltage states by 100% (adding complexity) and halves the increase in storage capacity itself.
| SLC (1 bit) | MLC (2-bit) | TLC (3-bit) | QLC (4-bit) | PLC (5-bit) | HLC (6-bit, theoretical) | |
| Differential storage capacity | Base line | +100% | +75% | +50% | +25% | +12.5% |
| Increased delta complexity | Base line | +100% | +100% | +100% | +100% | +100% |
“Today, we are pleased to show the industry’s first PLC SSD in action.” Sanjay Talreja, senior vice president and general manager of Solidigm’s Client Storage Group, said: This is an important milestone for Solidigm as a new company and an exciting moment for the future of storage technology with far-reaching implications. “
Solidigm’s PLC NAND is based on Intel technology, so it uses a different type of cell than what other major NAND players such as Micron have focused on. Intel’s NAND is based on floating gate transistors, which Solidigm says is good for creating PLCs with more bits per cell. Micron, like most of the NAND industry, has focused manufacturing on charge trap technology, which has its own strengths and weaknesses.
It’s unclear at this time when exactly PLC-based drives will hit the market. Western Digital has put it on record that it won’t hit the market until 2025, but in 2022 he has a working prototype from Solidigm. But when they arrive, customers can expect NAND drives with a better $/GB ratio than what the cheapest QLC drives can expect to offer. If you think it should be relegated to , think again. One of his most efficient and fastest SSDs we’ve tested so far, the SK hynix Platinum P41 is from Solidigms’ parent company. PLC SSDs will probably struggle in terms of performance, but as controllers and buses mature, we expect them to offer better performance at more affordable prices.
