Western Digital Launches the WD Black SN770 DRAM-less NVMe SSD

[bug]

It sure is coming, i think most laptop ssds are going to be qlc, and they want to sneak qlc to desktop with vage marketting and bait, and switch best selling drives to qlc, its a slow boiling frog situation

What really worries me is that ever since its introduction, I haven't heard of single improvement to QLC technology. You know, something to enhance durability, boost writes... They're working on PLC instead.

 

[lexluthermiester]

It sure is coming, i think most laptop ssds are going to be qlc

No. QLC is garbage. They can release it, but no one who understands NAND durability will knowingly buy it.

What really worries me is that ever since its introduction, I haven't heard of single improvement to QLC technology.

That's because their hasn't been any and there will not be much. The chemistry of NAND limits durability, especially at the voltage levels needed for QLC functionality.

 

[TheLostSwede]

That's easily explained. The actual power draw is unknown ATM. However, with the absence of a DRAM chip, power draw is certain to be lower.

The comparison from WD was that the SN770 is 20% more power efficient than the SN750 SE.

 

[BSim500]

Give them couple of months to pull a bait and switch and you will see SN770 with QLC flash.

The first thing I do with all new SSD's now is go straight to the manufacturers site and download the data sheet. If it (plus related marketing materials) completely lacks any official description of "TLC", then it leaves the door open to a TLC -> QLC bait & switch later on without any legal comeback ("well technically, we've never actually marketed or sold the drive specifically as having to be TLC, so...") As much as people bash "Samsung prices" (and I agree with them), at least the 980 specifically states "3-bit" NAND vs an ocean of manufacturers who now actively remove all mention of TLC, QLC, 3-bit, etc, information even from "data sheets" of new drives...

 

[bug]

That's because their hasn't been any and there will not be much. The chemistry of NAND limits durability, especially at the voltage levels needed for QLC functionality.

That's what we thought about TLC and then someone had the idea to go 3D. Yes, we're kinda running out of dimensions, but who knows?, unlikely as that may be, someone smarter than me may come up with a novel idea again

 

[Solid State Soul ( SSS )]

No. QLC is garbage. They can release it, but no one who understands NAND durability will knowingly buy it.

Mlc was absent from new ssd releases since 2020 and the 980 pro despite all the outrage it sparked for being downgrade to TLC, is still moving from the shelvs.
Am not a fan but its going to happen

 

[bug]

Mlc was absent from new ssd releases since 2020 and the 980 pro despite all the outrage it sparked for being downgrade to TLC, is still moving from the shelvs.
Am not a fan but its going to happen

The thing is, 3D TLC is about as durable as planar MLC. No problem replacing one with the other. QLC on the other hand has both low endurance and and poor writes. And while it's fine as a storage/main drive, I wouldn't want to be forced to install my OS on such a drive.

 

[TheLostSwede]

And we have a review. They're not seeing any power usage reduction, but it seems quite capable for a DRAM-less drive.

WD Black SN770 SSD Review: A Wolf in Sheep's Clothing (Updated)

Stellar performance, especially for gamers.

www.tomshardware.com

 

[trsttte]

And we have a review. They're not seeing any power usage reduction, but it seems quite capable for a DRAM-less drive.

WD Black SN770 SSD Review: A Wolf in Sheep's Clothing (Updated)

Stellar performance, especially for gamers.

www.tomshardware.com

Hmm I'd really like a Wizzard review, the rosy performance numbers seem to hide some very uggly things, like the drive is able to use the entire nand as SLC giving very good performance at 4,850 MBps for the first ~377gb, but then it degrades to 560 MBps

How will it perform when it's almost full and there's little SLC to take advantage off? Another case of "give'em more slc and they won't notice the missing dram?" perhaps?

 

[bug]

And we have a review. They're not seeing any power usage reduction, but it seems quite capable for a DRAM-less drive.

WD Black SN770 SSD Review: A Wolf in Sheep's Clothing (Updated)

Stellar performance, especially for gamers.

www.tomshardware.com

Tbh, I wasn't expecting much in the way of power usage. Irl, drives don't draw much power, next to CPU or display. On top of that, SSDs are mostly idle. If you don't improve that (which is already pretty low), it won't matter whether you're drawing 2W instead of 3W for the tenth of a second it takes to save that xls.

 

[lexluthermiester]

That's what we thought about TLC and then someone had the idea to go 3D.

But that is due to a new way to manufacture NAND cells, not a new chemistry. Making a NAND cell in 3 dimensions instead of the traditional 2 only means that we can not turn a cell on it's end and pack more of them in together. It did nothing for durability.

Am not a fan but its going to happen

No, it isn't. Durability is a serious problem for QLC. Unless a breakthrough in the chemistry is made, durability is going to continue to suffer. QLC will continue to be garbage.

The thing is, 3D TLC is about as durable as planar MLC.

No, it isn't. The idea is a myth.

 

[TheLostSwede]

But that is due to a new way to manufacture NAND cells, not a new chemistry. Making a NAND cell in 3 dimensions instead of the traditional 2 only means that we can not turn a cell on it's end and pack more of them in together. It did nothing for durability.

You seem to have a very short memory if you claim that, as the move to 3D TLC vastly improved the durability.
I'm not going to suggest it's as good as MLC, but it ended up somewhere between MLC and planar TLC, which made it a lot more acceptable.

 

[bug]

But that is due to a new way to manufacture NAND cells, not a new chemistry. Making a NAND cell in 3 dimensions instead of the traditional 2 only means that we can not turn a cell on it's end and pack more of them in together. It did nothing for durability.

It worked wonders for durability. As the cell gets increasingly smaller, so does the charge they can hold. Splitting that charge 3 ways instead of 2 was a real problem at first. But when TLC went 3D, the cell got bigger and it could hold a larger charge again.

Of course, that was a one trick pony, we're now looking to split the charge 4 or 5 ways and the charge itself is again shrinking as the manufacturing nodes shrink.

 

[lexluthermiester]

You seem to have a very short memory if you claim that, as the move to 3D TLC vastly improved the durability.

"Vastly" is an exaggeration. IIRC, the difference is about 6% to 8%. While that's not insignificant, it doesn't qualify as vast. Additionally, if you look up the change over for most companies to 3D NAND also required a chemistry change.

It worked wonders for durability. As the cell gets increasingly smaller, so does the charge they can hold

No it didn't. The benefit of going 3D was the die space used. It allowed for cell density to increase without using more power or shrinking the lithography process. The chemistry had to change with it and there was an improvement to the formulation, but these aspects were more coincidence, not intentional.

This article gets it right.

Difference Between SLC, MLC, TLC & QLC NAND SSDs: Which One is Better? | Hardware Times

If you want a top-of-the-line system, especially for gaming or content creation, then an SSD is absolutely necessary. However, before you go hunting for one, you should know what to look for. There are multiple different types of SSDs. As far as the basic SSD storage cells are concerned, you’ve...

www.hardwaretimes.com

Remember, QLC durability is measure in the 600 to 700 P/E cycle range. That is unacceptable as a boot/OS/daily-use drive.

 

[bug]

"Vastly" is an exaggeration. IIRC, the difference is about 6% to 8%. While that's not insignificant, it doesn't qualify as vast. Additionally, if you look up the change over for most companies to 3D NAND also required a chemistry change.


No it didn't. The benefit of going 3D was the die space used. It allowed for cell density to increase without using more power or shrinking the lithography process. The chemistry had to change with it and there was an improvement to the formulation, but these aspects were more coincidence, not intentional.

This article gets it right.

Difference Between SLC, MLC, TLC & QLC NAND SSDs: Which One is Better? | Hardware Times

If you want a top-of-the-line system, especially for gaming or content creation, then an SSD is absolutely necessary. However, before you go hunting for one, you should know what to look for. There are multiple different types of SSDs. As far as the basic SSD storage cells are concerned, you’ve...

www.hardwaretimes.com

Remember, QLC durability is measure in the 600 to 700 P/E cycle range. That is unacceptable as a boot/OS/daily-use drive.

Actually, that article get it completely wrong. 3D NAND is about the 3D structure of a cell (which is what increases the charge capacity). He has that confused with multilayered NAND which is about taking NAND cells, whether planar or 3D, and layering them on top of each other. This is mostly about packaging, so you don't end up with a 1 sq m die.

 

[lexluthermiester]

Actually, that article get it completely wrong. 3D NAND is about the 3D structure of a cell (which is what increases the charge capacity). He has that confused with multilayered NAND which is about taking NAND cells, whether planar or 3D, and layering them on top of each other. This is mostly about packaging, so you don't end up with a 1 sq m die.

Allow me to restated, he gets the quotes on durability correct.

 

[bug]

H

Allow me to restated, he gets the quotes on durability correct.

How could he, when he doesn't know what he's talking about?
Here's some more realistic numbers: https://en.wikipedia.org/wiki/Flash_memory#Write_endurance
Keep in mind those a skewed a bit in favor of SLC and MLC, because those were made back when we used older processes, thus cells were physically bigger.

 

[lexluthermiester]

H

How could he, when he doesn't know what he's talking about?
Here's some more realistic numbers: https://en.wikipedia.org/wiki/Flash_memory#Write_endurance
Keep in mind those a skewed a bit in favor of SLC and MLC, because those were made back when we used older processes, thus cells were physically bigger.

I'm done with this back & forth.

Back to the original point, if you want to buy QLC go right ahead. Expect your drive not to last very long.

 

[TheLostSwede]

"Vastly" is an exaggeration. IIRC, the difference is about 6% to 8%. While that's not insignificant, it doesn't qualify as vast. Additionally, if you look up the change over for most companies to 3D NAND also required a chemistry change.


No it didn't. The benefit of going 3D was the die space used. It allowed for cell density to increase without using more power or shrinking the lithography process. The chemistry had to change with it and there was an improvement to the formulation, but these aspects were more coincidence, not intentional.

This article gets it right.

Difference Between SLC, MLC, TLC & QLC NAND SSDs: Which One is Better? | Hardware Times

If you want a top-of-the-line system, especially for gaming or content creation, then an SSD is absolutely necessary. However, before you go hunting for one, you should know what to look for. There are multiple different types of SSDs. As far as the basic SSD storage cells are concerned, you’ve...

www.hardwaretimes.com

Remember, QLC durability is measure in the 600 to 700 P/E cycle range. That is unacceptable as a boot/OS/daily-use drive.

These are "old" figures now though, as it's only for second generation 3D TLC.

https://archive.eetasia.com/www.eetasia.com/ART_8800716703_499486_TA_b73ee3ee_2.HTM

Also, I thought we were discussing TLC vs 3D TLC, QLC can get stuffed.

 

[lexluthermiester]

These are "old" figures now though, as it's only for second generation 3D TLC.
View attachment 235120

https://archive.eetasia.com/www.eetasia.com/ART_8800716703_499486_TA_b73ee3ee_2.HTM

Also, I thought we were discussing TLC vs 3D TLC, QLC can get stuffed.

If those numbers are correct, then 3DTLC is dramatically more durable than has been commonly known. Didn't know this myself. Kind surprising and hard to believe.

 

[Solid State Soul ( SSS )]

No, it isn't. Durability is a serious problem for QLC. Unless a breakthrough in the chemistry is made, durability is going to continue to suffer. QLC will continue to be garbage.

Maybe, but those QLC intel NVMe drives are selling like hot cakes, i think it was even a newegg select item( most purchased ), yet aside for average speeds, there isnt any quality complaints, and intel has had liek 3 generations of it now, 660p, 665p, and 670p, all are 5 eggs on newegg

Look am just being realistic here, mainstream people dont care about TLC QLC MLC, they just care about what is the newste drive from mt favorit company that is affordable and they buy what is a QLC drive without knowledge, companies see this and they double down on that ... it is what it is

But hey we are on an enthusiast forms so we an inform each other on good drives to buy

 

[bug]

If those numbers are correct, then 3DTLC is dramatically more durable than has been commonly known. Didn't know this myself. Kind surprising and hard to believe.

That's what we were trying to tell you: you had the wrong/stale data. It happens, it's not like we have a built-in RSS feed for every data we ever memorized. It could be kinda cool if we did, tho.

 

[TheLostSwede]

If those numbers are correct, then 3DTLC is dramatically more durable than has been commonly known. Didn't know this myself. Kind surprising and hard to believe.

Note the temperature. So not under normal consumer usage temperatures.
Again, this is also compared to what was maybe the worst MLC as on 1xnm-ish it was starting to have some issues.
But yes, 3D TLC isn't the same as TLC when it comes to durability.

 

[lexluthermiester]

But yes, 3D TLC isn't the same as TLC when it comes to durability.

I'm not arguing that, but 20,000 P/E cycles @85C? That's a tough one to accept. 2,000 would be believable. And I can not find any supporting data anywhere else. It would be nice if 20kP/E was true, but where is the verifying data?

 

[TheLostSwede]

I'm not arguing that, but 20,000 P/E cycles @85C? That's a tough one to accept. 2,000 would be believable. And I can not find any supporting data anywhere else. It would be nice if 20kP/E was true, but where is the verifying data?

Yeah, I agree that number does look a tad high, but Micron says more than 10K P/E cycles and that data is a few years old as well. The 20K figure seems to be related to some "industrial" 3D TLC NAND flash and might not translate directly to SSDs.

3D NAND uses a larger cell size than the most recent planar NAND flash generations. With this larger cell size, the number of electrons per bit of data in TLC 3D NAND is the same or better than the latest nodes of MLC 2D NAND, so the endurance and data retention is roughly equivalent. TLC 3D NAND has demonstrated more than 10,000 program/erase cycles with robustness suitable for many applications. For automotive applications with extremely rugged usage environments, the requisite 3000 program/erase cycles can be achieved across a very broad temperature range, with prolong product life.

TLC 3D NAND Flash: High-performance, cost-effective automotive solutions

NAND-based solutions are ubiquitous for cloud storage, but automotive solutions seem to be taking a different evolutionary path.

www.micron.com