[LoganDark]

> Your comment, along with other users, suggests that TLC is a positive attribute for consumers

TLC is better than QLC, which is specifically what my comment was addressing; I never implied that it's better than SLC though, so just don't, please.

It's interesting to see that 3D-NAND has other issues even when run in SLC mode, though.

[drtgh]

> I never implied that it's better than SLC though, so just don't, please.

My apologies.

> It's interesting to see that 3D-NAND has other issues even when run in SLC mode, though.

Basically the SSD manufacturers are increasing capacity by adding more layers (3D-NAND). When one cell is read in the vertical stack, the interferences produced by the traces in the area increases the cells that need to be rewritten, what consumes the life of the device, by design.

[wtallis]

> When one cell is read in the vertical stack, the interferences produced by the traces in the area increases the cells that need to be rewritten, what consumes the life of the device, by design.

You should try being honest about the magnitude of this effect. It takes thousands of read operations at a minimum to cause a read disturb that can be fixed with one write. What you're complaining about is the NAND equivalent of DRAM rowhammer. It's not a serious problem in practice.

[drtgh]

Not NAND equivalent as the larger the stack, the larger the writings on the continuous cells, not just rewriting a single cell.

Here, the dishonest are the SSD manufacturers of the last decade, and they are feeling so comfortable as to introduce QLC into the market.

> It's not a serious problem in practice.

It's as serious as in to read data consume the disk, and the faster its read the faster it's consumed [0]. You should have noticed that SSD disks no longer come with a 10-year warranty.

    "under low throughput read-only workloads, SSD-A/-B/-C/-D/-E/-F extensively rewrite the potentially-disturbed data in the background, to mitigate the read (disturbance) induced latency problem and sustain a good read performance. Such rewrites significantly consume the already-reduced SSD lifetime. "

Under low throughput read-only workloads.

It is a paper from 2021, what means sci-hub can be used to read it.

[0] https://dl.acm.org/doi/10.1145/3445814.3446733

[wtallis]

> It's as serious as in to read data consume the disk, and the faster its read the faster is consumed

Numbers, please. Quantify that or GTFO. You keep quoting stuff that implies SSDs are horrifically unreliable and burning through their write endurance alarmingly fast. But the reality is that even consumer PCs with cheap SSDs are not experiencing an epidemic of premature SSD failures.

EDIT:

> You should have noticed that SSD disks no longer come with a 10-year warranty.

10-year warranties were never common for SSDs. There was a brief span of time where the flagship consumer SSDs from Samsung and SanDisk had 10-year warranties because they were trying to one-up each other and couldn't improve performance any further because they had saturated what SATA was capable of. The fact that those 10-year warranties existed for a while and then went away says nothing about trends in the true reliability of the storage. SSD warranties and write endurance ratings are dictated primarily by marketing requirements.

[drtgh]

In a 2min search,

https://www.reddit.com/r/DataHoarder/comments/150orlb/enterp...

    "So, on page 8's graphs, they show that 800GB-3800GB 3D-TLC SSDs had a very low "total drive failure" rate. But as soon as you got to 8000GB and 15000GB, the drives had a MASSIVE increase in risk that the entire drive has hardware errors and dies, becomes non-responsive, etc."

Study: https://www.usenix.org/system/files/fast20-maneas.pdf

(with video): https://www.usenix.org/conference/fast20/presentation/maneas

[wtallis]

Would you care to explain how any of that supports the points you're actually making here?

Some of what you're spamming seems to directly undermine your claims, eg.:

> Another finding is that SLC (single level cell), the most costly drives, are NOT more reliable than MLC drives. And while the newest high density 3D-TLC (triple level cell) drives have the highest overall replacement rate, the difference is likely not caused by the 3D-TLC technology

[Dylan16807]

The massive increase is still 1/500 chance per year.

[LoganDark]

> When one cell is read in the vertical stack, the interferences produced by the traces in the area increases the cells that need to be rewritten, what consumes the life of the device

So 3D-NAND suffers interference between the stacked layers? (Introducing Columnhammer... /s)