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Comment by mapt | Hacker News Reader

Write endurance of the drive would be measured in TBW, and TLC flash kept adding enough 3D layers to stay cheap enough, quickly enough, that Optane never really beat their pricing per TBW to make a practical product.

I have to wonder if it isn't usable for some kind of specialized AI workflow that would benefit from extremely low latency reads but which is isn't written often, at this point. Perhaps integrated in a GPU board.

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Optane practical TBW endurance is way higher than that of even TLC flash, never mind QLC or PLC which is the current standard for consumer NAND hardware. It even seems to go way beyond what's stated on the spec sheet. However, while Optane excels for write-heavy workloads (not read-heavy, where NAND actually performs very well) these are also power-hungry which is a limitation for modern AI workflow.

You're conflating two things. Yes, Optane would survive more writes. But it wouldn't survive more TBW/$, because much larger flash drives were available cheaper. Double the size of the drive using identical technology, and you double TBW ratings.

This was very clearly not true at the time for the actual implied TBW figures of even a tiny Optane drive, and is not even true today when you account for the much lower DWPD of TLC/QLC media. Do the math, $1/GB vs $0.1/GB where the actual difference in DWPD per spec sheets is more like two or three orders of magnitude, with the real-world practical one being quite possibly larger. (Have people even seen Optane actually fail in the wild due to media wear out? This happens all the time with NAND.)

> it wouldn't survive more TBW/$

Yes it would, by an almost arbitrarily large margin. You can test this out for yourself. Overwrite one of each in an endless loop. Whenever the flash based drive fails, replace it and continue. See how long it takes for the optane to fail.

You should be able to kill a typical consumer flash drive in well under a week. Even high end enterprise gear will be dead within a couple of months.

The extra capacity of modern SSD is a good point, especially now that we have 100TB+ SSD.

But Optane still offered 100 DWPD (drive writes per day), up to 3.2TB. Thats still just so many more DWPD than flash ssd. A Kioxia CM8V for example will do 12TB at 3 DWPD. The net TBW is still 10x apart.

You can get back to high endurance with SLC drives like the Solidigm p7-p5810, but you're back down to 1.6TB and 50 DWPD, so, 1/4 the Intel P5800X endurance, and worse latencies. I highly suspect the drive model here is a homage, and in spite of being much newer and very expensive, the original is still so much better in so many ways. https://www.solidigm.com/content/solidigm/us/en/products/dat...

You also end up paying for what I assume is a circa six figure drive, if you are substituting DWPD with more capacity than you need. There's something elegant about being able to keep using your cells, versus overbuying on cells with the intent to be able to rip through them relatively quickly.

We don't care about (TBW/TB) at the consumer level, we care about (TBW/$), and 3D TLC was far, far cheaper per TB, so much so that TBW/$ was not a numerical advantage of Optane.

That left ONLY the near-RAM-read-latency, which is only highly beneficial on specific workloads. Then they didn't invest in expanding killer app software that could utilize that latency, and didn't drop prices sufficiently to make it highly competitive with big RAMdisks.

In 2018, with Optane drives launching around $1.50/GB and TLC flash drives around $0.15/GB, it wasn't that much cheaper. As far as I'm aware Optane had a lot more than 10x the endurance.

10x endurance and 10x latency reduction, for 10x the price. It was closer to 5x the price with the closeout firesale after it was killed.

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