News SK Hynix Reveals 238-Layer 3D NAND: Cheap and Fast SSDs Incoming

MeeLee

Distinguished
Aug 27, 2014
78
8
18,545
0
"4D NAND"???
Let's not get ahead of ourselves, just because someone does 238 layers of what initially started as SLC, and evolved to DLC, TLC and now MLC.
MLC nand, be it 3D or regular, can have a very large amount of layers. To become 4D nand, it'd have to shape shift in our realm, and I don't see that happening anytime soon.
 

bit_user

Splendid
Ambassador
"4D NAND"???
Let's not get ahead of ourselves, just because someone does 238 layers of what initially started as SLC, and evolved to DLC, TLC and now MLC.
MLC nand, be it 3D or regular, can have a very large amount of layers. To become 4D nand, it'd have to shape shift in our realm, and I don't see that happening anytime soon.
I sympathize with your sentiment, but just want to point out that I think the PUC is how they justify calling it "4D". Not that it makes much more sense, but I guess the idea is they're not only stacking layers of NAND, but also putting the controller underneath it all. So, that extra degree of stacking somehow qualifies it as "4D".

Or, maybe it's intended to refer to the fact that they're packing multiple bits per cell. So, to address a bit, you'd need to specify the: plane, x coordinate, y coordinate, and which bit in the cell. However, I think it's not their first 3D TLC or at least MLC chip, so it's a little hard to see why it would suddenly now qualify as 4D.

Another way you can justify calling something "4D" is if the interconnect topology warrants it. But nothing about that is mentioned.
 

ASK THE COMMUNITY