Samsung starts mass production of first 4-bit SSDs for consumers

[midian182]

Something to look forward to: With the size of games getting ever larger, are you finding yourself running out of storage space? If so, here’s some good news from Samsung. The Korean giant has announced that it is now mass producing the industry’s first 4-bit QLC (quad-level cell) SSDs for consumers, which may lead to cheaper high-capacity drives.

Jaesoo Han, Executive VP of Memory Sales and Marketing at Samsung, said: “Samsung’s new 4-bit SATA SSD will herald a massive move to terabyte-SSDs for consumers. As we expand our lineup across consumer segments and to the enterprise, 4-bit terabyte-SSD products will rapidly spread throughout the entire market.”

Samsung’s QLC SSDs are based on the firm’s 1Tb 64-layer V-NAND used in its TLC flash, which stores three bits per cell.

With the amount of data being stored in each cell increasing from three bits to four, performance and speed of the new SSDs were expected to decrease. But Samsung says its upcoming 4-bit 4TB QLC SSD boasts the same performance as a 3-bit SSD. It achieves this by using a 3-bit SSD controller and TurboWrite technology.

Samsung specifies that its 4-bit QLC SSD has a sequential read speed of 540 MB/s and a sequential write speed of 520 MB/s, but it doesn’t mention random I/O speeds or endurance figures.

Samsung says the new drives will be available in 1TB, 2TB, and 4TB capacities in a 2.5-inch SATA form factor. The company added that it is also working on a 128GB QLC memory card for smartphones. No word yet on prices or release dates.

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https://www.techspot.com/news/75846-samsung-starts-mass-production-first-4-bit-ssds.html

 

[BSim500]

"Samsung specifies that its 4-bit QLC SSD has a sequential read speed of 540 MB/s and a sequential write speed of 520 MB/s, but it doesn’t mention random I/O speeds or endurance figures."

I'm more concerned about unpowered data retention. It's one thing to use these as a system drive that gets booted up every day that can background self-correct any voltage drift, but quite another to market them as some 1:1 "replacement" for HDD's used as external cold-storage backup drives that only get plugged in occasionally. You can throw unchanging data like wedding photo's, etc, onto a HDD and shove it away in a drawer for 5-10 years no problem. Powered SSD's can refresh as needed. But is the old "guaranteed 12 months" JEDEC guidelines for unpowered SSD's made back in the era of large node MLC drives already lower with small node TLC? Is it down to weeks / months with QLC where the thresholds between voltage states vs charge leak drifts halve again?

It would be nice if tech sites went back to serious testing for this stuff beyond just copy / paste empty PR statements whilst complaining about omitted facts (like missing endurance ratings presumably because QLC drops it off from thousands of rewrites to just hundreds even with extreme error correction...)

 

[hood6558]

Intel's QLC endurance is rated for 100-200 drive writes. That doesn't leave any room for re-write schemes, like Samsung had to implement on their TLC drives when read speeds decreased as cells leaked voltage. External cold storage could be a real problem for QLC, leaving us with only expensive options for archiving important files on SSD (SLC or MLC). TLC and QLC need a lot more testing to determine data retention after years, before it can be considered safe for archival purposes, if ever. What's really needed is a new kind of NAND, designed for one write and infinite reads, with unlimited cold data retention and cheaper than DVD. You know, like the data cubes in all the science fiction books/movies that last thousands of years.