Much like an onion, the more layers the more mass and volume. In this case, NAND mass storage. A while ago SK Hynix already shared word that they delivered the first samples of its solution products based on its 128-layer NAND. As it turns out, they might be ready for volume production already.
You need to understand that when you currently purchase a TLC based SATA3 or M.2 SSD, chances are pretty big it's using a 64-layer cell structure. Each layer holds a certain amount of storage cells, which are then written a number of bits (3 for TLC) per cell. So the more layers you stack, the more you can store in regards to storage density. 96-layers is already here and SK Hynix thus now might make an announcement for 128-layers next week at CES. So with 512 GB per 64-layer NAND IC, you'd now get 1024 GB.
The first two products are Gold P31 and Platinum P31 nvme-ssds and will use this new 128-layer memory. SK hynix didn't reveal any further details about the SSDs, though.
SK Hynix Likely to announce first 128-layer NAND P31 M.2 SSDs next week already