New generation: Solidigms QLC offers 192 layers and more writing performance

As part of the specialized Storage Field Day 24 event, Solidigm announced the upcoming fourth generation of QLC NAND flash with floating gate architecture acquired from Intel. The number of levels (layers) is increased from 144 to 192 for even more bits per area. Also, random writing needs to be massively sped up.

The Solidigm presentation slides shared by Stephen Foskett on Twitter don’t reveal everything, but they do reveal some details about the new QLC-NAND, which claims to inherit Intel’s third generation with 144 layers. Actually, it is only the second generation after the separation of Intel and Micron, since the previous two generations of 64 and 96 layers were designed jointly by both companies.

And some performance numbers… #SFD24 pic.twitter.com/WvjeGbzQQq

— Stephen Foskett (@SFoskett) November 3, 2022

QLC with 192 layers

With the new generation, the number of cell layers increases from 144 layers to 192 layers. This should ensure a further increase in areal density, but more information is missing, such as the storage capacity per die and its size. Intel’s 144-layer QLC-NAND already offered a very high density of 13.8 gigabits/mm², but Kioxia (BiCS6) and SK Hynix (V7) already surpass it.

Significantly accelerated random write

As Kioxia and Samsung also point out, the performance of QLC-NAND should increase at the same time, which is clearly at a disadvantage compared to TLC-NAND. With the 192L-QLC-NAND, Solidigm even wants to beat the inexpensive (value) TLC-NAND by 24 percent in random write. Compared to the competitor’s unspecified QLC-NAND, the throughput or IOPS for random write should even increase by a factor of 6. Latency is 84 percent lower and well below 1 ms. Intel specified around 1.6 ms for the predecessor, as the table below shows.

Double your storage space with enterprise SSDs

Solidigm also talks about a possible doubling of the SSD storage capacity from a maximum of 30.72 TB to 61.44 TB. Whether this means memory chips now store 2 terabits or simply fit twice as many into a NAND package remains to be seen. Until now, all QLC variants have offered 1 terabit per die, which is now also being achieved by Micron’s new 232L-TLC-NAND, which even beats the 144L-QLC-NAND in terms of areal density.

QLC often persistent enough

Solidigm highlights the fact that the durability of QLC-NAND is sufficient for many areas with the fact that most TLC-SSDs are said to be specified with less than 1 Drive Write Per Day (DWPD) at 85 percent. This means that these can be fully subscribed under the guarantee less than once a day.

Although the potential write cycles with QLC are lower, they would not pose a risk even with many enterprise applications, Solidigm continues.

“Solidigm QLC SSDs provide ample endurance compared to TLC SSDs. 85% of SSDs today ship with less than 1 DWPD of endurance…and for the vast majority of enterprise users. cycle of QLC PE do not represent any risk”. #SFD24 @TechFieldDay Tune in! https://t.co/px6j6z5dkG pic.twitter.com/p9jl7CPdwB

— Solidigm (@solidigm) November 3, 2022