Re: What will be the data retention lifetime?
I do wonder how adding more and more layers to a single cell affects it's lifespan though.
However, amortised across an entire 4TB SSD, lower write endurance should be acceptable for anything outside very high write I/O loads. e.g. database logs, caches in front of large arrays, etc, which is what SLC or Optane or other future technologies like MRAM are for.
Depending on source, typical max program-erase cycles are:
SLC 50k-100k > eMLC 20k-30k > MLC 5k-10k > 3DTLC 1k-10k > pTLC 1-5k > QLC 0.1k-0.5k (aka hundreds, not thousands).
SLC: Single-level cell, 1b/cell
eMLC: enterprise-class Multi-level cell, 2b/cell
MLC: Multi-level cell (consumer-class), 2b/cell
3DTLC: 3-d (stacked) Three-level cell, 3b/cell
pTLC: planar (2D, non-stacked) Three-level cell, 3b/cell
QLC: Quad-level cell, 4b/cell