Earlier this week Samsung announced that it has begun mass production on its first consumer solid state drive based on QLC (4 bits per cell) V-NAND. According to the company, the initial drives will offer 4TB capacities and deliver equivalent performance to Samsung’s TLC offerings along with a three year warranty.

Samsung claims that its fourth generation V-NAND flash in QLC mode (with 16 voltage states) with 64 layers is able to offer up to 1Tb per chip. The 4TB SATA SSD uses a 3-bit SSD controller, TurboWrite technology, and 32 1Tb QLC V-NAND chips and thanks to the write cache (running the V-NAND in SLC or MLC modes) Samsung is able to wring extra performance out of the drive though it’s obviously limited ultimately by the SATA interface. Specifically, Samsung is promising sequential reads of 540 MB/s and sequential writes of up to 520 MB/s with the new QLC SSD. For comparison, Samsung’s fourth generation V-NAND operating in TLC mode is able to offer up to 256Gb and 512Gb capacities depending on package. Moving to fifth generation V-NAND in TLC mode Samsung is offering 256Gb per chip capacities (using 96 layers). Scouring the internet, it appears that Samsung has yet to reveal what it expects to achieve from 5th generation V-NAND in QLC mode. It should be able to at least match the 1Tb of 4th generation QLC V-NAND with the improved performance and efficiencies of the newer generation (including the faster Toggle DDR 4.0 interface) though I would guess Samsung could get more, maybe topping out at as much as 1.5Tb (eventually and if they use 96 layers–I was finding conflicting info on this). In any event, for futher comparison, Intel and Micron have been able to get 1Tb QLC 3D NAND flash chips and Western Digital and Toshiba are working on 96 Layer BiCS4 which is expected to offer up to 1.33Tb capacities when run in 4-bits per cell mode (QLC).

It seems that Samsung is playing a bit of catch up when it comes to solid state storage using QLC though they do still have a bit of time to launch products this year along with the other players. Samsung claims that it will launch its 4TB 2.5” consumer SSD first with 1TB and 2TB models to follow later this year.

Interestingly (and more vaguely), Samsung mentioned in its press release that it plans to begin rolling out M.2 SSDs for the enterprise market and that it will begin mass producing fifth generation 4-bit V-NAND later this year.

I am looking forward to more details on Samsung’s plans for QLC and especially on the specifications of fifth generation 4-bit V-NAND and the drives that it will enable for both consumer systems and the data center markets.

What are your thoughts on Samsung’s QLC V-NAND?

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