Everyone is spouting TBW when percentage used is what manufacturer set to be the warranties lifetime. Go read the smart specs.
No one talking about NAND types (SLC,MLC,TLC,QLC) or one of the hybrid types (pSLC, iTLC, etc) which can be difference between 1k and over 100k P/E cycles.
My guess is this behaviour is (mostly) by design, using high bandwidth mass storage as some awesome high performance virtual memory.
Why are people complaining about 1-3% wear in 2 months when used as a dev machines, or running a hundred tabs in chrome? That’s still over 5 years usage within expected lifetime on very heavily used machines, and it could be even higher in reality.
It actually swaps much more than the older machine that I have, at 3% wear already. And the indicator isn't linear.
(at 30TB written currently, 250TB and the machine risks failure when estimating from a machine which actually failed from this already)
In those machines, Apple just uses TLC flash from Toshiba/Kioxia (off-the-shelf).
Like others, you are comparing to some dated, off the shelf, consumer SSD (980 pro).
It is CLEARLY not regular consumer TLC given the figures reported. It will be using some pSLC type arrangement (iTLC?), otherwise percentage used would be considerably higher given TBW.
True story: I bought a 256GB 960EVO ~4 years ago strictly for the performance, I've written 50TB, and it shows 100%. I think temperature might have something to do with the percentage. I replaced it with a 1TB Hynix P31 for the same price (~$100) recently. 1TB MLC/TLC drives were ~$400+ when I bought the 960EVO, so I'm not mad. If I couldn't replace it, I just might be. The TLC has improved this much between the two drives: 1200MB/s vs 1700MB/s sustained write, 1.5x random read IOPS, almost 2x TBW rating compared to 1TB 960EVO.
The 960EVO hasn't started to slow down yet or use it's reserved space, so I imagine I can keep using it as an external drive until it does.
edit: What I've said is indicative of an TLC/PCIE 3 NVMe upgrade path, what will a PCIE 4 NVMe (980PRO) upgrade look like in 4 years?
Its not a case of "lasting", its a case of warranty. That is SPECIFICALLY what "percentage used" is for! What SSD can you buy that has a warranty longer than 5 years? Do your other devices stop working when out of warranty? Why do people think these will?
2) This field is specifically for warranties - go read the spec. All manufacturers use this in their warranty - its actually coded into the controller. They may report the value to you in TBW, but that same value is stored in the controller, which is where the percentage comes from. If you think otherwise, why dont you point me at the apple warranty that states the number of TBW.
