What SSDs have 3D QLC NAND?

[cbn]

So far here are the consumer models I have found....

1.) Intel 660p (PCIe 3.0 x 4 NVMe with 256MB dram buffer, SM2263 controller)
2.) Crucial P1 (PCIe 3.0 x 4 NVMe with dram buffer, SM2263 controller)
3.) ADATA SU 630 ultimate (SATA, dram-less and uses Intel 3D QLC NAND and Maxio Technology MAS0902A controller )
4.) Samsung 860 QVO (SATA with dram buffer)

 

[whm1974]

I'm not I would bother using QLC type SSDs at all. Don't they have severe limitations?

 

[cbn]

I'm not I would bother using QLC type SSDs at all. Don't they have severe limitations?

Right now I am sorta thinking of 3D QLC as the "planar TLC" of the 3D NAND world......and one thing I am wondering about is voltage drift from unpowered DATA retention. (Last generation 15nm TLC was the best according to Glaring_Mistake's findings......but what will happen this generation?)

 

[whm1974]

Right now I am sorta thinking of 3D QLC as the "planar TLC" of the 3D NAND world......and one thing I am wondering about is voltage drift from unpowered DATA retention. (Last generation 15nm TLC was the best according to Glaring_Mistake's findings......but what will happen this generation?)

I have wondering since I read a few reviews of QLC SSDs if at 7nm if we will go back to using SLC and MLC NAND for SSDs?

 

[VirtualLarry]

About that Adata SU630 SATA 3D QLC NAND SSD...

What kind of bottom-of-the-barrel garbage is that going to be? If it's QLC, then it had better be for "bulk storage", and not an OS drive that needs to handle paging and tempfiles and browser cache files, and it needs to be 1TB+ sizes, not some shlocky 240GB.

I would be willing to go with an Adata XPG SX6000 or 8000 or 8200 M.2 PCI-E NVMe 512GB SSD for an OS drive, and then an SU630 1TB/2TB/3TB/4TB for a mass-storage drive.

But NOT an SU630 for an OS drive, which is all I can figure the smaller sizes are aiming for. Either that, or OEMs. Would they even bother with this garbage?

 

[cbn]

Yes, DRAM-less SATA SSD increases wear and tear.

https://www.tomshardware.com/reviews/dramless-ssd-roundup,4833.html

"Unfortunately, DRAMless SSDs also have a sinister side. Updating the map directly on the flash requires small random writes, which takes a bite out of the SSD's endurance. This is a particularly vexing issue with low endurance planar 2D TLC NAND flash. At Computex last June, one SSD vendor told us about an OEM 2D TLC SSD that will burn through the rated endurance in a little over a year. The SSD has to last a year because of the notebook's one-year warranty, but anything beyond a year's worth of use is up to the user to fix. Tactics like that are the driving forces behind putting cheap DRAMless SSDs in $500 notebooks."

.....and, yes, being an OS drive would increase those writes.

P.S. Nice thing about NVMe dram-less is that it can use the system RAM via Host memory buffer. This. of course, reduces wear compared to what a DRAM-less SATA SSD would receive under the same conditions.

 

[mxnerd]

ADATA drives only offer 2 years warranty, Intel & Crucial offer 5.

 

[VirtualLarry]

I've got an Adata SP550 240GB SATA SSD in this box. Is that DRAM-less? I know it's 2D TLC. I've got 8.01TB written, according to the Adata toolbox.

 

[cbn]

I've got an Adata SP550 240GB SATA SSD in this box. Is that DRAM-less? I know it's 2D TLC. I've got 8.01TB written, according to the Adata toolbox.

That one has SM2256.....so dram-buffer.

 

[whm1974]

Yes, DRAM-less SATA SSD increases wear and tear.

https://www.tomshardware.com/reviews/dramless-ssd-roundup,4833.html

"Unfortunately, DRAMless SSDs also have a sinister side. Updating the map directly on the flash requires small random writes, which takes a bite out of the SSD's endurance. This is a particularly vexing issue with low endurance planar 2D TLC NAND flash. At Computex last June, one SSD vendor told us about an OEM 2D TLC SSD that will burn through the rated endurance in a little over a year. The SSD has to last a year because of the notebook's one-year warranty, but anything beyond a year's worth of use is up to the user to fix. Tactics like that are the driving forces behind putting cheap DRAMless SSDs in $500 notebooks."

.....and, yes, being an OS drive would increase those writes.

P.S. Nice thing about NVMe dram-less is that it can use the system RAM via Host memory buffer. This. of course, reduces wear compared to what a DRAM-less SATA SSD would receive under the same conditions.

I simply will not use dram less SSDs at all. Or for that matter QLC SDDs either.

 

[cbn]

Here is post from Tom's about using Optane in front of 3D QLC with regard to endurance:

https://www.tomshardware.com/news/intel-optane-memory-qlc-cache,37223.html

"Sitting behind high-endurance Optane Memory (cache) will remove any immediate concerns regarding QLC's endurance."

 

[VirtualLarry]

I simply will not use dram less SSDs at all. Or for that matter QLC SDDs either.

You might be surprised. Toshiba TR200 240GB SATA SSD is DRAM-less, but it actually performs pretty decently, for the short time that I was testing it.

 

[whm1974]

You might be surprised. Toshiba TR200 240GB SATA SSD is DRAM-less, but it actually performs pretty decently, for the short time that I was testing it.

What about write endurance?

 

[cbn]

I simply will not use dram less SSDs at all. Or for that matter QLC SDDs either.

You might be surprised. Toshiba TR200 240GB SATA SSD is DRAM-less, but it actually performs pretty decently, for the short time that I was testing it.

What about write endurance?

Toshiba TR200 has 3D TLC.

 

[whm1974]

Toshiba TR200 has 3D TLC.

Performance is pretty low for the TR200 especially with larger sizes.

 

[cbn]

Performance is pretty low for the TR200 especially with larger sizes.

What metric are you referring to? (Looking through the Anandtech review I noticed the QD1 Sequential Write had a pronounced difference between the 960GB and the lower sizes).

 

[SimplyComplex]

These drives aren't nearly cheap enough to justify the risk profile. 3D QLC is getting into some pretty scary error rates that requires an amazing amount of controller correction. I sense the next wave of Sandforce style failures are coming from this tech. Just reading the internal electrical specs on these things made me uneasy.

From a purely performance standpoint, they aren't bad at all. But when I look at all that controller is tasked with... man I don't see these things being very reliable. I'd expect even in the best case scenario to see 1st gen consumer MLC ssd life expectancy from these.

 

[thecoolnessrune]

Yeah personally I'm doing the same as planar TLC and waiting for the second gen QLC drives. More adventurous folks can work through the teething.

Samsung's upcoming 4TB QLC drive looks more promising, and sounds pretty interesting for building a dense, 2.5" NAS.

 

[VirtualLarry]

I'd expect even in the best case scenario to see 1st gen consumer MLC ssd life expectancy from these.

Which, discounting SandForce controller/firmware "issues" that randomly popped up, most early MLC NAND drives survived around 5 years or more. That wouldn't be a bad lifespan for a larger QLC drive, IMHO.

 

[SimplyComplex]

most early MLC NAND drives survived around 5 years or more. That wouldn't be a bad lifespan for a larger QLC drive, IMHO.

While true recall how most of those 1st gen drives would go out. It works on year 4 day 121 perfectly. Then you turn your computer on and the drive is gone without any way to access a thing on there any more.

Hopefully these QLC drives are more recoverable, but I have a bad feeling about them. And I've been fiercely pro-ssd for ages. I've always thought ssds were more stable and secure than platter HDDs going back to 2009. This is the first ssd tech that's given me concerns. Considering we have perfectly stable 3d TLC nand, I can't imagine choosing QLC over it. They may be fine for a server in raid, but as a consumer I have no interest in them.

 

[VirtualLarry]

While true recall how most of those 1st gen drives would go out. It works on year 4 day 121 perfectly. Then you turn your computer on and the drive is gone without any way to access a thing on there any more.

Hopefully these QLC drives are more recoverable, but I have a bad feeling about them. And I've been fiercely pro-ssd for ages. I've always thought ssds were more stable and secure than platter HDDs going back to 2009. This is the first ssd tech that's given me concerns. Considering we have perfectly stable 3d TLC nand, I can't imagine choosing QLC over it. They may be fine for a server in raid, but as a consumer I have no interest in them.

That's technically true for ANY consumer SSD. In fact, I don't think that I've ever seen one that I would consider "recoverable". (Although, I mean by the end-user, using "recovery software" - I don't work in the lower-level recovery biz.) Not like a HDD is, by any means.

 

[SimplyComplex]

That's technically true for ANY consumer SSD. In fact, I don't think that I've ever seen one that I would consider "recoverable". (Although, I mean by the end-user, using "recovery software" - I don't work in the lower-level recovery biz.) Not like a HDD is, by any means.

When my 2013 made ssd failed, I had several days warning. First it warned me of problems. A few days later it locked itself into "read only" mode. It did not just up and die. Which is what usually happened in 1st gen drives. There was no sign of problems and instant failure.

 

[hojnikb]

Yes, DRAM-less SATA SSD increases wear and tear.

https://www.tomshardware.com/reviews/dramless-ssd-roundup,4833.html

"Unfortunately, DRAMless SSDs also have a sinister side. Updating the map directly on the flash requires small random writes, which takes a bite out of the SSD's endurance. This is a particularly vexing issue with low endurance planar 2D TLC NAND flash. At Computex last June, one SSD vendor told us about an OEM 2D TLC SSD that will burn through the rated endurance in a little over a year. The SSD has to last a year because of the notebook's one-year warranty, but anything beyond a year's worth of use is up to the user to fix. Tactics like that are the driving forces behind putting cheap DRAMless SSDs in $500 notebooks."

.....and, yes, being an OS drive would increase those writes.

P.S. Nice thing about NVMe dram-less is that it can use the system RAM via Host memory buffer. This. of course, reduces wear compared to what a DRAM-less SATA SSD would receive under the same conditions.

Having no DRAM in an SSD shouldn't increase wear all that much. Remember, while DRAM does buffer translation tables, they still need to be updated regularly in the flash, because otherwise you'd loose data when removing power and SSD hadn't had the time to flush it's contents from DRAM.

 

[hojnikb]

These drives aren't nearly cheap enough to justify the risk profile. 3D QLC is getting into some pretty scary error rates that requires an amazing amount of controller correction. I sense the next wave of Sandforce style failures are coming from this tech. Just reading the internal electrical specs on these things made me uneasy.

From a purely performance standpoint, they aren't bad at all. But when I look at all that controller is tasked with... man I don't see these things being very reliable. I'd expect even in the best case scenario to see 1st gen consumer MLC ssd life expectancy from these.

Even older 2D flash required a lot of ERROR correction to be usable. Other than very old SLC flash, everything had some sort of error rate that was considered normal and just had to be dealt by controller.

As long as controllers can manage the error rate, thats nothing wrong. Honestly, i'd be more concerned if someone had the guts to put out sub 20nm 2D QLC. That would be scary useless.
(to be fair, we already had 2D QLC waaaay back in 2009. but was fabbed on a much larger node and only used in SD cards).

 

[whm1974]

Even older 2D flash required a lot of ERROR correction to be usable. Other than very old SLC flash, everything had some sort of error rate that was considered normal and just had to be dealt by controller.

As long as controllers can manage the error rate, thats nothing wrong. Honestly, i'd be more concerned if someone had the guts to put out sub 20nm 2D QLC. That would be scary useless.
(to be fair, we already had 2D QLC waaaay back in 2009. but was fabbed on a much larger node and only used in SD cards).

Even so since SSDs are still more expensive per GB then HDDs are, and QLC hasn't been that well tested, I'll stick with the best brands/models of TLC based SSDS that offer at least a 5 year warranty.