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Micron's 232-layer NAND enables 2TB flash chips that deliver data 50% faster

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Re: Micron's 232-layer NAND enables 2TB flash chips that deliver data 50% faster

#3

At what point will the wear resistance be so low from increasing the layers (and bits) per cell that flash becomes effectively write-once, read many (WORM)?

Levels per cell and wear I understand. What's the link between circuit layer depth and wear?

Re: Micron's 232-layer NAND enables 2TB flash chips that deliver data 50% faster

#4

At what point will the wear resistance be so low from increasing the layers (and bits) per cell that flash becomes effectively write-once, read many (WORM)?

Keep in mind, these are layers of cells, not multi-level cells. Each of the layers has an individual multi-level cell.

That said, Samsung quad-level cells only have 1k write lifetime, so likely not far off.

Re: Micron's 232-layer NAND enables 2TB flash chips that deliver data 50% faster

#5

At what point will the wear resistance be so low from increasing the layers (and bits) per cell that flash becomes effectively write-once, read many (WORM)?

Increasing layers should cause roughly zero problems.

As far as bits per cell, 4 already gives you very slow writes and not a lot of them. Let's say that maxes out at 5 or 6.

Re: Micron's 232-layer NAND enables 2TB flash chips that deliver data 50% faster

#6
post #4

At what point will the wear resistance be so low from increasing the layers (and bits) per cell that flash becomes effectively write-once, read many (WORM)?

Keep in mind, these are layers of cells, not multi-level cells. Each of the layers has an individual multi-level cell. That said, Samsung quad-level cells only have 1k write lifetime, so likely not far off.

I love how someone said there's a septuple-level cell out there... but you have to immerse it in liquid nitrogen for it to work.

Re: Micron's 232-layer NAND enables 2TB flash chips that deliver data 50% faster

#7
post #4

At what point will the wear resistance be so low from increasing the layers (and bits) per cell that flash becomes effectively write-once, read many (WORM)?

Keep in mind, these are layers of cells, not multi-level cells. Each of the layers has an individual multi-level cell. That said, Samsung quad-level cells only have 1k write lifetime, so likely not far off.

Remember, even 1000 writes means roughly 3Y of full drive writes per day with the naïve wear leveling and the most brutal write load. For most write loads the drives made of this kind of NAND can be easily warranted for 3Y.

Re: Micron's 232-layer NAND enables 2TB flash chips that deliver data 50% faster

#8

At what point will the wear resistance be so low from increasing the layers (and bits) per cell that flash becomes effectively write-once, read many (WORM)?

There was a paper a while back that promised a healing process for flash:

https://www.zdnet.com/article/self-healing-flash-for-infinit...

I have no idea what happened to that though, because it sounded extremely promising.

Re: Micron's 232-layer NAND enables 2TB flash chips that deliver data 50% faster

#9
post #7
post #4

Earlier quoted context omitted.

Keep in mind, these are layers of cells, not multi-level cells. Each of the layers has an individual multi-level cell. That said, Samsung quad-level cells only have 1k write lifetime, so likely not far off.

Remember, even 1000 writes means roughly 3Y of full drive writes per day with the naïve wear leveling and the most brutal write load. For most write loads the drives made of this kind of NAND can be easily warranted for 3Y.

Yeah, 1K is still in the range of reasonable (if the wear leveling isn't terrible), another order of magnitude decrease though and we're getting on the edge of not.

Re: Micron's 232-layer NAND enables 2TB flash chips that deliver data 50% faster

#10

At what point will the wear resistance be so low from increasing the layers (and bits) per cell that flash becomes effectively write-once, read many (WORM)?

Increasing layers should cause roughly zero problems. As far as bits per cell, 4 already gives you very slow writes and not a lot of them. Let's say that maxes out at 5 or 6.

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