Toshiba produces the world's first 4-bit QLC NAND Flash Memory

[Agosto]

2 hours ago, Sakkura said:

For a comparison point to more regular usage, I've had a 120GB SSD since 2012, and it has 28TB of writes on it. That's 4% of its lifespan according to the SMART statistics, meaning it's internally rated for about 700TBW. Which would last me about another 120 years at this rate.

Is it an Intel 335?

[Sakkura]

42 minutes ago, Agost said:

Is it an Intel 335?

OCZ Agility 3. Was a few months before Intel released the 335, plus I was on a tight budget. Same SF-2281 controller though; everyone was using Sandforce back then.

[DocSwag]

23 hours ago, The Benjamins said:

 

 

 

Ya and this is for increase capacity so if the durability goes down by half but now you get 2x more space the endurance of the drive would stay the same.

 

and remember their was a endurance test done were even the worst 250GB drives lasted more then 400 TB written to it. so I think a 1-2TB QLC drive will be fine.

This is incorrect, you don't get 2x more space. It's instead 4/3x more space (4 bpc vs 3 bpc). And durability doesn't necessarily go down by half. TLC, for example, was generally around 3x less durable than mlc.

[Agosto]

1 hour ago, Sakkura said:

OCZ Agility 3. Was a few months before Intel released the 335, plus I was on a tight budget. Same SF-2281 controller though; everyone was using Sandforce back then.

You're very lucky, those drives were quite unreliable IIRC

[Zodiark1593]

3 hours ago, Sakkura said:

OCZ Agility 3. Was a few months before Intel released the 335, plus I was on a tight budget. Same SF-2281 controller though; everyone was using Sandforce back then.

Think even my PNY Optima drive from 2014 in my loaner laptop is using Sandforce as well (which ironically, is higher performing than with the controller it was supposed to have). 

[Juanitology]

7 hours ago, Sakkura said:

And the rated endurance is very conservative, the underlying NAND is rated for far more writes.

 

For a comparison point to more regular usage, I've had a 120GB SSD since 2012, and it has 28TB of writes on it. That's 4% of its lifespan according to the SMART statistics, meaning it's internally rated for about 700TBW. Which would last me about another 120 years at this rate.

 

It's MLC though, but then again if it was QLC the capacity would be doubled. People don't seem to realize that although newer tech (more bits per cell, smaller process node) often reduces the write endurance, the increasing capacity partially counteracts that trend.

 

I wouldn't really want a 120GB SSD based on QLC, but at more realistic capacities it's fine for consumer use.

I don't know any specifics, but from what I understood QLC gives 1/3 more space for less than half the endurance, so in that case it might not be worth it unless they can do some insane wear-leveling magic at the controller level or maybe only use QLC on the next-gen nvme protocol which has some features to split streams into separate blocks to have a much lower wear level on the NAND itself.

[Sakkura]

15 minutes ago, Terodius said:

I don't know any specifics, but from what I understood QLC gives 1/3 more space for less than half the endurance, so in that case it might not be worth it unless they can do some insane wear-leveling magic at the controller level or maybe only use QLC on the next-gen nvme protocol which has some features to split streams into separate blocks to have a much lower wear level on the NAND itself.

Well if the endurance drops from "enough for 50 years" to "enough for 20 years" is that really such a grievous loss?

[The Benjamins]

8 hours ago, DocSwag said:

This is incorrect, you don't get 2x more space. It's instead 4/3x more space (4 bpc vs 3 bpc). And durability doesn't necessarily go down by half. TLC, for example, was generally around 3x less durable than mlc.

what I mean is as long as the total writes is reasonable I am fine with it.

[DocSwag]

2 hours ago, The Benjamins said:

what I mean is as long as the total writes is reasonable I am fine with it.

Dats probably fair. Endurance isn't my main concern anyways as I don't see it becoming unreasonably low, it's mainly the potentially large performance dropoff we might see that kinda worries me.

[The Benjamins]

1 minute ago, DocSwag said:

Dats probably fair. Endurance isn't my main concern anyways as I don't see it becoming unreasonably low, it's mainly the potentially large performance dropoff we might see that kinda worries me.

ya.

 

me personally I want as big of a SSD I can afford at SATA speeds. NVME is nice but I don't feel the speed in every day tasks.