I'm not even sure what the bit I highlighted means but I remember the 840 EVO bug...
It's silly to write the brand off over an issue years ago
It wasn't really bug, but feature resulting from pushing tech too hard.
All semiconductors are made on silicon substrate, with components builts as layer on its surface.
Semiconductor grade silicon (impurities measured in few parts per billion) is just very expensive.
So to fit more circuitry (or in this case storage capacity) into same surface area, manufacturers push component sizes down.
That has major negative side effecs for use as Flash memory:
When transistors were becoming smaller and smaller, amount of charge they could store in their insulated floating gate was becoming smaller. (less tolerance for leakage)
While also insulation got weaker and weaker making that memory "cell" less durable and worser at retaining charge.
Single Level Cell (SLC) storing only one bit needs to only differentiate between empty and full charge, which is easy to read/write and has lots of tolerance for degradation.
Multi Level Cell (MLC) was next step storing second bit per cell and requiring distinguishing between four charge states lowering tolerance for charge leakage and other degradation.
Triple Level Cell (TLC) crammed third bit into cell requiring eight charge levels.
And that simply exceeded capabilities of tiny transistors, with those smaller charges degrading over time after write.
Errors from that degradation again started causing increasing amount of re-reads and stressed error corrections more and more causing drive slowing down.
In 3D-NAND instead of single layer on silicon's surface components are built into vertical structures with multiple layers on top of each others.
That allows using bigger (and better) transistors while decreasing size of silicon chip per capacity.
Which brought TLC's reliability back to level of planar MLC.
Hence no 840 EVO like problems in succeeding EVOs, or in any of the countless TLC drives of other makers.
Quad Level Cell (QLC) crams now fourth bit into that cell.
And naturally writing and reading 16 different charge levels is lot harder than same for eight charge levels.
While tolerance for charge degradation/transistor wear etc. is very small.
That's feature of technology itself.
And reason why it would be completely silly to pay anything approaching TLC price, or same price, for technically lot worser QLC.
No matter the brand.
And in this case Samsung's QLC drive is more expensive than TLC drives of others.
