SSD's got even bigger? PLC nand

[The1Dickens]

So, with these PLC drives: Would they not use a SLC or MLC smaller chip (say, 32 or 64 GB) to have those better write speeds, and after the write operation, it would offload that to the larger umpteen-TB PLC storage? I mean, I don't know business people, but I'd imagine that someone would do something like this to be able to claim superiority in the market. The SLC or MLC bit could also store the important part of the information on the drive, and maybe help with error correction or something? Maybe its wishful thinking.

[Origami Cactus]

8 minutes ago, The1Dickens said:

So, with these PLC drives: Would they not use a SLC or MLC smaller chip (say, 32 or 64 GB) to have those better write speeds, and after the write operation, it would offload that to the larger umpteen-TB PLC storage? I mean, I don't know business people, but I'd imagine that someone would do something like this to be able to claim superiority in the market. The SLC or MLC bit could also store the important part of the information on the drive, and maybe help with error correction or something? Maybe its wishful thinking.

No, that is not the case.

The current QLC drives run some QLC cells as SLC cells, but the size changes as the drive fills up. If the 512gb 660p is about 80% the slc bit is only 5gb.

But yes, the bigger the drive, the less noticable the qlc speed is, as the dynamic slc cache is bibiggergfer.

 

But if we actually had some massive qlc or plc drives that wouldn't be a problem, as if you have a 8tb drive you could effectively run like a quarter tb for the slc part.

[dfsdfgfkjsefoiqzemnd]

2 hours ago, Lady Fitzgerald said:

While dramatically overkill, I make sure my backup drives get powered up and read at least once a month, especially the ones that have static data on them, to avoid the danger of corrupting or losing data due to charge leakage during downtime.

That's never a bad idea. 

That being said, I recently plugged in the 240GB 840EVO (TLC) that holds my old rig's Win7 install.  That drive had been in a drawer for 6 months and it still booted just fine.  Even the video files in the download folder played without any visible or audible artifacts.  And that model is known for slowing down due to charge leakage if data was kept static, even if the drive was powered on. 

Didn't do any checksums though, so I can't verify that there was no bitrot at all.  I'll do some next year when I put it back in storage at the end of the winter (end of folding season).

[Lady Fitzgerald]

10 minutes ago, Captain Chaos said:

That's never a bad idea. 

That being said, I recently plugged in the 240GB 840EVO (TLC) that holds my old rig's Win7 install.  That drive had been in a drawer for 6 months and it still booted just fine.  Even the video files in the download folder played without any visible or audible artifacts.  And that model is known for slowing down due to charge leakage if data was kept static, even if the drive was powered on. 

Didn't do any checksums though, so I can't verify that there was no bitrot at all.  I'll do some next year when I put it back in storage at the end of the winter (end of folding season).

Well, I did say it was overkill. 

 

I don't worry about bit rot and check sum since my data backup program (FreeFileSync) will pick up any differences between files between the data disk and the backup, which would show up in the versioning folder. Frequently updating backups makes checking the versioning folder easy.

[Guest]

7 hours ago, VegetableStu said:

dear fucking everyone,

 

1LC. 2LC. 3LC. 4LC. 5LC.

 

fucking thanks,

Dr. WTF IS PLC

Can’t wait for the SSD DLC

[Zodiark1593]

49 minutes ago, Origami Cactus said:

No, that is not the case.

The current QLC drives run some QLC cells as SLC cells, but the size changes as the drive fills up. If the 512gb 660p is about 80% the slc bit is only 5gb.

But yes, the bigger the drive, the less noticable the qlc speed is, as the dynamic slc cache is bibiggergfer.

 

But if we actually had some massive qlc or plc drives that wouldn't be a problem, as if you have a 8tb drive you could effectively run like a quarter tb for the slc part.

The problem of wear occurs due to the granularity required to read the voltage from tye cells. Could cells that are too worn for QLC/PLC use be dynamically repurposed as SLC cells?

[Augustin]

6 hours ago, leadeater said:

WD VelociRaptors

before i could save up enough to buy these drives they had become obsolete

[Kisai]

50 minutes ago, Lady Fitzgerald said:

Well, I did say it was overkill. 

 

I don't worry about bit rot and check sum since my data backup program (FreeFileSync) will pick up any differences between files between the data disk and the backup, which would show up in the versioning folder. Frequently updating backups makes checking the versioning folder easy.

That's why I compared it to tape backup. If your normal use case is to just cycle drives out, then 4LC and 5LC probably just fine, because they'll stay in the machine until they need to be sent to a secure storage facility. 

 

Ideally, you wouldn't put anything but SLC or MLC in performance/high-reliability systems. TLC is this weird middle-ground where it's unusable for high performance servers and HEDT, but probably good enough for infrequently written to storage arrays, or laptops that use "modern standby" . 

 

With that said, I held off buying SSD's and didn't recommend them for high-reliability systems due to experiences with them on servers where they die annually. I just can't recommend using them on web servers or anything that has a high level of random writing.

 

If you just throw away the drive after 10 full backups or so, then then that's no worse than using tapes.

[TechyBen]

7 hours ago, huilun02 said:

Maybe by 2023 we will be back to regular old mechanical drives

dohecahedroncellathon... an entire HDD per cell on the chip.

 

PS hopefully this becomes an option for mixed cells in an SSD. So consumer grade would have 1 nice speedy controller, Some RAM, 1 or 2 nice faster chips, and the rest could be slower PLC? That might be a better option?

 

[Vorg]

Reliability is far more important than speed. To me, NAND is a dead end for this kind of storage. They should stop wasting resources trying to squeeze more out of it and move on.

I keep hoping Micron will get off their butts and start kranking out 3d XPoint/QuantX memory for SSD's. That is a step in the right direction. They cry about it being too costly to compete, but that's only because they won't mass produce it on the level that brings it down to the cost of nand.

 

And Intel is brain dead trying to use it for system ram. That goes back to the same problem using nand for drives. When they can get the reliability to that of static ram, then use it for system ram.

[leadeater]

1 hour ago, Augustin said:

before i could save up enough to buy these drives they had become obsolete

I had 4 of them in RAID 0, living on the edge lol

[Augustin]

Just now, leadeater said:

I had 4 of them in RAID 0, living on the edge lol

it is 100% OK to put games on RAID0. Worst case scenario you get an excuse to buy a box of beers on a weeknight and reinstall an operating system!

[hello_there_123]

9 hours ago, Origami Cactus said:

QLC is already really slow at only 80-120mb/s for sustained writes, so this will be even slower.

This is after you fill the SLC cache, which is already an *extremely* unlikely scenario for most consumers. 

 

Besides, in order for the 80-120mb/s to bottleneck you, you would have to be doing a massive file transfer with either gigabit ethernet or a local transfer between multiple drives. 

[leadeater]

1 hour ago, Kisai said:

With that said, I held off buying SSD's and didn't recommend them for high-reliability systems due to experiences with them on servers where they die annually. I just can't recommend using them on web servers or anything that has a high level of random writing.

You're talking TLC here or consumer SSDs in general? I've never actually had a server SSD fail, had one Samsung 840 EVO fail but I abused that pretty badly in a system that didn't support TRIM.

[Augustin]

1 minute ago, leadeater said:

You're talking TLC here or consumer SSDs in general? I've never actually had a server SSD fail, had one Samsung 840 EVO fail but I abused that pretty badly in a system that didn't support TRIM.

i had a pair of early 60gb Intel drives. Can't remember exactly what they were but they were good quality for their time. I upgraded them for capacity before they died but they did eventually die about 6 or 7 years after I bought them. My point is: capacity & price of new drives made them obsolete before they died.

[hello_there_123]

9 hours ago, Origami Cactus said:

Because it will be slower than a hdd, but atleast it will be fully silent.

How would you know that?? Are you a future time traveller who has looked at the 4K rand r/w QD1 of various PLC SSDs and come back??

[hello_there_123]

9 hours ago, Origami Cactus said:

for example, Samsung's consumer drives are rated for up to 520MB/sec. 

You probably won't ever see that 520MB/s speed in real life, given that the speed advertised is peak sustained sequential QD32, while most consumers only care about (or should care about) 4K rand r/w QD1. 

[hello_there_123]

Overall I believe that the article was written mainly for people who actually give a crap about endurance (content creators, etc) but this comments section has spun that into "PLC slower than an HDD reeeeeee"

[dizmo]

6 hours ago, Origami Cactus said:

That is precisely the case, look at the durability differences between 1tb  samsung 860qvo (QLC), Samsung 860evo (TLC) and 860 pro (MLC).

The durability rating is still awfully good. The 1TB is rated at what, 330TB? Who even writes that much? It'd take many, many years to reach that point, and by then you'll have likely upgraded or swapped it out for something else.

3 hours ago, Donut417 said:

Is there a technical reason they cant just build SSD's bigger. Like 3.5 inch like standard hard disks size?

It's not needed? It's not like it'd save costs or something.

[Origami Cactus]

22 minutes ago, hello_there_123 said:

This is after you fill the SLC cache, which is already an *extremely* unlikely scenario for most consumers. 

 

Besides, in order for the 80-120mb/s to bottleneck you, you would have to be doing a massive file transfer with either gigabit ethernet or a local transfer between multiple drives. 

12 minutes ago, hello_there_123 said:

How would you know that?? Are you a future time traveller who has looked at the 4K rand r/w QD1 of various PLC SSDs and come back??

9 minutes ago, hello_there_123 said:

You probably won't ever see that 520MB/s speed in real life, given that the speed advertised is peak sustained sequential QD32, while most consumers only care about (or should care about) 4K rand r/w QD1. 

7 minutes ago, hello_there_123 said:

Overall I believe that the article was written mainly for people who actually give a crap about endurance (content creators, etc) but this comments section has spun that into "PLC slower than an HDD reeeeeee"

 

 

 

 

You know that you can quote multiple things at once, instead of spamming posts?

 

Now lets get into it:

1) You know that the SLC cache size reduces dramatically as you fill up the drive right? Not hard to fill up 6gb.

Just look at this graph: But i agree, for normal users it is fine, especially if the drive is not near full.

Spoiler

2) I have a QLC SSD, and that thing only does 80mb/s writes, and PLC will be about 2x as slow, so rip. But Random writes will still probably be better than HDD, and small writes will be ok thanks to the SLC cache.

3) Have you never used a samsung SSD? I see 520mb/s all the time, even if the drive is full, the problem with samsung 860 evo is that it is bottlenecked by the SATA interface, especially the higher capacity models

4) There just isn't any need for the downgrade that is PLC right now, it doesn't save enough money to justify it's downsides, unless they finally come out with 8TB+ consumer drives. The highest QLC drive is currently 4TB? I hoped to see atleast a 10TB drive.

 

TLDR: Yes, PLC has it's use cases, but the increase in complecity over QLC downplays the small size increase.

[MadDuke]

Personally. 

 

I just want the capacity for the cheapest price.  Then one day simply go Optane for the OS and main apps and a large few TB for storage. 

[dfsdfgfkjsefoiqzemnd]

1 hour ago, dizmo said:

The 1TB is rated at what, 330TB? Who even writes that much? It'd take many, many years to reach that point, and by then you'll have likely upgraded or swapped it out for something else.

Many SSDs will happily do a multitude of the rated write endurance. 

 

As for who writes that much and how long it takes to wear out an SSD, I just did a Crystal Disk Info check of my old 1TB 840EVO, which is mostly used for multiplexing fresh Blu-Ray rips and editing audio files.

Spoiler

48TB written in just over 5 years (I bought that drive in August 2014), with 0 reallocated sectors and 100% drive health still.

Samsung doesn't give a maximum write endurance for this drive, but the 250GB version in Techreport's endurance test died shortly before hitting 900TBW. 

At this rate I'll need 88 more years to hit that 900TBW number.  Seeing as I'll be well into my 120s by then, I'll probably wear out long before the NAND does.

[ARikozuM]

10 hours ago, Origami Cactus said:

Space increase per cell increase:

SLC 

MLC +100%

TLC +50%

QLC +25%

PLC +20%?

QLC +33%

PLC +25%

 

Can we just go to NVMe already? At some point, SATA will be a bottleneck with its queuing ability. 

[porina]

49 minutes ago, MadDuke said:

Then one day simply go Optane for the OS and main apps and a large few TB for storage. 

That's my game system you just described. I have an Optane 600P 280GB for OS, and Crucial 1TB + Sandisk 960GB SSDs for game storage, as well as HDs for less important stuff.

 

Lessons learnt: 

Optane makes no noticeable performance difference compared to a decent flash SSD for OS/gaming uses. You can detect a difference in benchmarks but you can't really feel it.

It is worth putting all large games on SSD than HD. That loading time difference is noticeable. 

 

For those wondering about endurance, according to SMART I've written 6.6TB to the Sandisk, and 3.3TB to the Crucial. The Sandisk Ultra II was bought November 2015, so nearly 4 years old. They don't give an endurance rating for that model, but Anandtech testing estimates it above 400TB, so I'm over 1% into it. The Crucial MX200 was bought August 2015, so somehow I've written less to it even though it is slightly older? Maybe it just happens the games I put on there happen to require fewer updates, and/or I change what is installed less. They do rate theirs at 320TBW so again I'm just over 1% wear on that.

 

Back to these PLC SSDs, it is likely for game storage scenarios, endurance is not going to be a problem, and nor is read speed. Write speeds for normal use should be ok as you're not going to hammer it with large writes all the time. 

[dizmo]

1 hour ago, Captain Chaos said:

Many SSDs will happily do a multitude of the rated write endurance. 

 

As for who writes that much and how long it takes to wear out an SSD, I just did a Crystal Disk Info check of my old 1TB 840EVO, which is mostly used for multiplexing fresh Blu-Ray rips and editing audio files.

 

48TB written in just over 5 years (I bought that drive in August 2014), with 0 reallocated sectors and 100% drive health still.

Samsung doesn't give a maximum write endurance for this drive, but the 250GB version in Techreport's endurance test died shortly before hitting 900TBW. 

At this rate I'll need 88 more years to hit that 900TBW number.  Seeing as I'll be well into my 120s by then, I'll probably wear out long before the NAND does.

Oh, definitely. That's what I was saying. The endurance of drives is insane. If it's rated at 330TBW, it's been quoted as such with a wide margin, and will likely last much, much longer. On my laptop, which granted I don't use that often for huge files and such, but has had numerous games installed on it and loads and loads of movies, and is 7 years old, has 19TBW. The desktop I have now that gets a lot of games installed on it only has 11TB written to it over a year. So, as you say, the drives are nearly indestructible from a regular wear use standpoint. It'd take me 25 or 30 years to reach the "suggested" EOL rating...by the SSDs will have likely been replaced by something entirely different.