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Kioxia Researchers Demo Hepta-Level Cell NAND Flash, Nearly Doubling the Capacity of QLC
NAND researchers at Kioxia have successfully demonstrated a working concept of a new storage architecture called Hepta-level cell NAND flash. This new type of NAND can house up to 7 bits per cell, giving it nearly twice the storage capacity of QLC NAND flash. If Kioxia can stabilize this storage architecture at room temperature, it might become the ultimate successor to spinning hard drives in consumer and enterprise applications.
To create hepta-level NAND flash, Kioxia is using a new design called new silicon process technology to increase cell density, in conjunction with cryogenic cooling. New silicon process technology replaces current poly-silicon materials with a single-crystal silicon that is used in a channel inside a memory cell transistor. This apparently reduces the amount of read noise coming from the NAND flash by up to two-thirds. In other words, new silicon process technology produces clearer read signals for reading data off of the NAND flash, enough so to increase the bits cell capacity to 7.
(Image credit: Kioxia)
Kioxia says this new storage architecture will also be significantly cheaper to produce, and even has a proposed solution incorporating hepta-level flash with cryogenic cooling. That would be cheaper than current (air-cooled or passively cooled) SSDs on the market today.
If Kioxia starts producing hepta-level NAND flash in the near future, it will likely change the SSD landscape forever. Ultra-high capacity SSDs will finally be possible, and SSDs will finally have the capacity to match most hard drives on the market today.
For perspective, the highest density NAND flash on sale today is QLC, with 4 bits per cell, used by drives like the Samsung 870 QVO 8TB SATA SSD, and the Sabrent Rocket 8TB NVMe SSD. With hepta-level flash, we could see drives almost as big as 16TB hitting consumer shelves (without other advancements, like more layers, which are also happening). The same could also apply to enterprise SSDs, with capacities that could match mainstream SAS hard drives.
But, speed and bandwidth (not to mention endurance) could be a potential issue with these future SSDs. We've seen this play out with QLC drives, where read and write speeds take a big hit compared to SLC, MLC, and TLC equivalents. If history repeats itself, this problem would likely become even worse with this new 7-layer hepta-level flash. Although for some instances where hard drives speeds have more or less been sufficient, that could be less of an issue.
We'll have to see how things play out, and what sort of solutions SSD manufacturers have in mind for circumventing these issues. In either case, hepta-level flash will at least need to have the same level of performance as hard drives to be competitive.
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Jump from 4 to 7 layers! if single layer is 2^1 2 voltage states, QLC is 2^4 is 16 voltage states, we are looking at 2^7 128 distinct voltage states... That is insane and Awesome,
wonder how many cycles one should expect before this can be marketed, 50? 100??
Either way I am looking forward to affordable 20tb SSD 🧀
Nope, can't deal with it being 7, must be 8 so divisible by two. OCD won't tolerate it otherwise. (In my defense one byte per cell does sound kind of kewl)
Current 16TB SSDs are ~$6000. Halve that, it is still ~$3000. A 16TB HDD on the other hand can be had for ~$300, 10X cheaper than the hypothetical 7-bits-per-cell SSD.
I'd be a little nervous about storing data on an SSD array that is perpetually one LN2 shortage away from spontaneously erasing itself.
Nope, can't deal with it being 7, must be 8 so divisible by two. OCD won't tolerate it otherwise. (In my defense one byte per cell does sound kind of kewl)
I'll be shocked if there isn't some small performance advantage to organizing flash into 1 byte per cell. Maybe not enough to overcome the effects of moving from hepta- to octa-, but still...
Nope, can't deal with it being 7, must be 8 so divisible by two. OCD won't tolerate it otherwise. (In my defense one byte per cell does sound kind of kewl)
So no TLC NAND for you then? Must be hard to find a drive to use right now. :)
This would be much slower sustained performance than QLC and less lifespan than QLC right?
QLC "real" speed are slower than HDD, which is sometimes avoided by consumers.
Then what's the point moving from HDD to this one?
This would be much slower sustained performance than QLC and less lifespan than QLC right?
correct.
why you got worse overall performance & durability (all things being same) as you went from SLC, MLC, TLC, & QLC.
they give up performance & durability for raw capacity and cheapness.
bjk8kds said:
QLC "real" speed are slower than HDD
depends on how they are built really.
and iirc for just reading data QLC is actually better than TLC. So work for data storage where you arent writing just reading from. Would likely be even better as we go from QLC to 7bit a cell from 4.
bjk8kds said:
Then what's the point moving from HDD to this one?
cost & Capacity in the long game.
SSD take up much smaller footprint than HDD. You can fit more into same physical space thus servers and the like benefit long term.
and personally I'd enjoy massive ssd (even if slow write) just for game library/backup drives. (and just copy/move data to faster drive when I want play it)
and personally I'd enjoy massive ssd (even if slow write) just for game library/backup drives. (and just copy/move data to faster drive when I want play it)
Needing to store your SSD in liquid nitrogen for data retention redefines cold data storage!
