...so, the 850Evo is guilty before the fact?
I stand corrected. No not guilty but under close scrutiny.
I hope the 850 Evo doesn't show the read degradation issue, I really do. But until enough time goes by without any negative reports I'm going to steer clear of them.
I'm no expert by any means but I'm thinking the bug/issue *could* proceed in the three steps outlined below. And by issue let's be clear, after data is written to the drive and not rewritten for a few months the voltage in the cells in question drop and the controller has a hard time figuring out the state of the cell. This results in multiple "trys" or rereads, which slows performance considerably.
1. Hopefully the controller just wasn't programmed correctly for these TLC NAND cells. That is taking the degradation into account. In this case Samsung just needs to reprogram the controller. It's a tough thing to diagnose/fix because you've gotta wait a few months in between trials!
2. Since we're only talking about a handful of electrons separating one level of these TLC cells from the next it might be that the read program is too aggressive (too fast) and the read process must be changed quite a bit. This could restore long-term performance consistency at the cost of overall performance. Of course this is a bad solution because it's not what buyers paid for, a very fast drive.
3. There is a serious problem with the TLC NAND and the drive is FUBAR for any long term storage. Total recall.
Looks like they already tried option #1 and thus far it hasn't worked. They will most likely try it again before heading to option #2 which the shit starts to hit the fan. It's unlikely this issue will proceed to #3 because I don't see Samsung making that big of a mistake. But in that case they will have a full blown shit show on their hands.