The write endurance of QLC is generally not a problem at higher capacities, at least for typical desktop usage scenarios where you are not writing hundreds of gigabytes to the drive every single day. With more capacity comes more cells to perform wear leveling across, so for capacities of around 1TB or more, QLC should have enough endurance to not be a real concern.Just hope the life of it is also the equivalent to SLC flash .
I think one thing people confuse a lot with this technology is that they assume it's different NAND - it's explicitly not. It's meant to be a drop-in change to existing flash. What you're talking about is 3D Xpoint (crossbar memory) which is a completely different thing than NAND. Although, X-NAND is decidedly not oriented at consumer usage.It did not happen unless it was tested by independent tester...
There has been Many promising new alternate to normal nand, but so far only Intel with Micron has come out with something like this... but at wery high cost...
so I hope for the best but am not holding my breath yet. Promising, but we need consumer products to make this real.
I'm not sure if you actually read the article, but at least according to what they are claiming...Imagine how good the memory would be if they put this kind of effort into improving good NAND instead of trying to "save" trash bottom-of-the-barrel QLC.
QLC is never going to be good enough or cheap enough to be worth buying over TLC. Anything that improves QLC can be used to improve TLC by an even wider margin, so it's always going to be worth paying that extra ~$20 for the much higher speeds and 10x the endurance... And that's just TLC, which is still bad compared to MLC and especially SLC, but at least in that case the price drop was actually more significant.
It always writes first in SLC mode, and further always at SLC speeds. There's three banks with the first writing incoming data to SLC, a second bank where SLC data is moved to QLC, and a third bank where SLC is erased to make room for more writes. The reason this works so well is because SLC mode tends to have a tPROG (write latency) of ~200µs - this applies to NAND in consumer drives as well, by the way - while QLC in his example is at a total of 6400µs (this is not precise, as newer consumer QLC can manage 1/2 to 1/3 this latency, but he's talking for all pages). Therefore you can write 32 SLC pages (e.g. 32x200µs = 6400µs) while keeping pace with data moving to QLC, therefore avoiding the SLC cache drop-off you usually see. This makes QLC uniquely qualified for this technology but that's also true of other characteristics - namely, if you're splitting 16KB pages into 4KB I/O chunks/subpages (16 / 4) and then the page buffer into 1KB chunks per plane (4 / 4), 4-bit QLC with 1-bit SLC is a match made in heaven.
- X-NAND makes QLC perform more like SLC.
- X-NAND dramatically improves the endurance of QLC.