CRamseyer :
The Optane drive can absorb all of the random writes if set up to do so. It used to be called Maximized Mode in RST Cache configurations. With all of the random writes going to Optane and then passed to the QLC as sequential data (that barely impact endurance compared to random data over the long term), the drive will last as long as what we have now.
I'm hearing the QLC endurance is actually much better than what most of us (the people commenting here and that actually care about technology) think it has. Part of that is due to stronger LDPC, but some of it is also due to a higher than expected number of PE cycles.
I'm not saying there's no way to design a storage device where the cache doesn't absorb a lot of the writes, like I said, having a cache there helps so we agree on that point. But you have to write to the QLC eventually just like you have to write to TLC. I assume that a drive using this 'maximized mode' with TLC or MLC would also have increased performance, so the performance gap would remain. It does sounds like something that would be interesting when paired with a 10TB spinning disk.
But if it 'used to' be called maximized mode, does that mean that somebody already tried to market the technology and it was rejected? I don't know much about it or why current drives do not operate that way, but would using Optane make it viable for consumer drives when it apparently wasn't when attempted with SLC? Optane is expensive, and the pitch for QLC is that it is supposed to be cheaper, so I don't know if anybody can find a balance where price/performance ever justifies that arrangement.
As for what the P/E of production QLC will be, that is weirdly hard to figure out. I have seen pre-production claims that 3D QLC may be capable of 1000 P/E cycles which would put it near planar TLC in terms of endurance, but still lower in speed - and who knows if they'll get there. Which is still pretty bad considering that planar TLC was already inferior. Granted, 1,000 P/E cycles is a whole lot better than the 100 P/E cycles that they were expecting when planar QLC was being attempted.
I was also having trouble figuring out the exact P/E cycles of current 3D TLC. I've seen a paper from 2015 claiming samsung's "second-gen" 3D TLC would reach 20k P/E cycles compared to 18k from their planar MLC. But I haven't been able to find a good source on if they ever reached that, and what is currently being used in consumer SSDs - I get the impression it lands somewhere in the 3k-5k range. A reduction from 3k to 1k is still very significant, even if it's not as bad as a drop from 20k down to 100.
From my perspective, it just looks like anything they can do to bring QLC to consumer drives with comparable endurance will be too costly, and would also improve TLC/MLC drives so the gap will remain - but it's a good thing too keep trying. That's how we'll get better SSDs overall, at least if they keep the other NAND technologies in production.
Realistically though, if QLC consistently meets the best-case performance claims, then they're just going to rush out a lot of slightly-cheaper low-performing drives with the warranty dropped down from 10 years down to 2 and sell them to people who don't know the difference.
People who are in the market for that kind of thing might be better off picking up a cheap planar TLC drive or two right now while you can still find them on clearance for $30.
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