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Update on Samsung SSD Reliability

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Re: Update on Samsung SSD Reliability

#162
post #77

The real problem is OS:es that write to disk for no good reason. Windows 10 writes 100KB/s constantly. That should be illegal.

Do we know the location of those writes, perhaps they can be redirected to a ramdisk?

management/windows logs about >100 active logs. Performance/data collector set about >50 active Event Trace Sessions running.

Re: Update on Samsung SSD Reliability

#163
post #109

I wish more independent review organizations would conduct destructive "write lifespan until ultimate failure" real world tests on SSDs. With a mixture of real world large contiguous files and small random writes. Real ultimate write lifespan on 3-level-cell and QLC consumer grade SSDs varies wildly for things of the same capacity and similar price. Such as this series of tests from 7 years ago: https://techreport.co…

>destructive "write lifespan until ultimate failure" real world tests on SSDs >from 7 years ago It's from 7 years back for good reason. They stopped doing those tests when it became impractical as endurance increased. The drives are now good enough that you can't wear them out fast enough to make sense in a review setting ...unless fundamentally broken like these

I find it highly improbable that you couldn't wear out a 3-level-cell or 4-level-cell consumer grade SSD which is capable of 300-500MB/s writes with a 24x7 automated test script in just a few months. Maybe even just a couple of weeks. The published total DWPD (drive-writes-per-day) endurance on these is not that great.

Even assuming a conservative 300MB per second, there's 86400 seconds in one day. That's 25920000 MB per day. Or close to 26TB per day. The samsung 960 Pro 2TB is rated by its manufacturer for a total 1200TB of write endurance lifespan.

Or at least leave it running for a couple of weeks and then see what the SMART-reported remaining write lifespan data reports it to be, versus the brand new out of box baseline.

Re: Update on Samsung SSD Reliability

#165

For the same price, you can get twice the space for 1/4 the endurance, thrice the space for 1/8th the endurance, and now four times the space for 1/16th the endurance. Most people don't realise that is a horrible tradeoff, because NAND flash marketing and terminology like "TLC" or "QLC" is intentionally deceptive and manufacturers have been very secretive about the true endurance specifications, as well as trying to…

For most people this isn't a horrible tradeoff. For example, my desktop which I use pretty heavily, I've averaged 24 GB writes per day. With 500 drive writes of a TLC drive, my ssd will last me roughly 50 years at current rate. If I had to chose between a 300 GB SSD that will last me 400 years or a 1TB ssd that lasts 50 years, I'll take the TB one any day of the week.

Re: Update on Samsung SSD Reliability

#166
post #82

Earlier quoted context omitted.

The value rising from 80 to 81 is an improvement. The calculated value decreases when the raw value of "Hardware ECC Recovered" worsens.

Is this the case for all SMART values? Higher=better?

Yes, the non-raw values are always reported with higher meaning better. The raw values are the raw measurements/counts and they each mean different things.

Re: Update on Samsung SSD Reliability

#167
post #138

For the same price, you can get twice the space for 1/4 the endurance, thrice the space for 1/8th the endurance, and now four times the space for 1/16th the endurance. Most people don't realise that is a horrible tradeoff, because NAND flash marketing and terminology like "TLC" or "QLC" is intentionally deceptive and manufacturers have been very secretive about the true endurance specifications, as well as trying to…

> as well as trying to overprice SLC out of production. Is it even possible to buy SLC drives any more? For the past 5+ years the only outlet I've been able to find that even advertise SLC is https://www.delkin.com/ , and you need to speak to sales to even get a price. I just assumed they and any other similar suppliers bought giant lots of chips at the tail end of SLC production and jack up the price on every new or…

In theory an SSD could run TLC NAND in SLC mode with just a firmware change but I'm not aware of any such drives.

Re: Update on Samsung SSD Reliability

#168

I've been trying to find a decent endurance NVME in the m.2 form factor for write-heavy applications and it appears that true 2-bit MLC has all but disappeared, replaced by 3-bit TLC and higher (with commensurate loss of endurance) The high endurance SSDs appear to be only available in u.2\u.3\hhhl and god-help-me EDSFF form factors Any suggestions? Micron's 7450 isn't readily available

Why not get a U.2 drive and an adapter like this one https://www.startech.com/en-us/hdd/m2e4sff8643

Didn't know such a thing existed, thank you!

Re: Update on Samsung SSD Reliability

#169
post #54

Apparently a few months ago it became known on the Chinese internet that the 980 Pro, 970 Evo Plus with new controller, and OEM versions are prone to getting unreadable sectors, where SMART 'Media and Data Integrity Errors' increases on every read attempt. https://www.reddit.com/r/buildapc/comments/x82mwe/samsung_ss... https://www.reddit.com/r/DataHoarder/comments/x8arle/psa_sam... How I came across this: Ran into th…

PS: I'm one of the victim with a 970 Evo Plus. The company that provided aftersell services, Lobcom, did not want to provide any RMA services and claimed nothing wrong is found.

The scamming company in question: https://zh.lobcomgroup.com/

Re: Update on Samsung SSD Reliability

#170

Earlier quoted context omitted.

On the other hand, lots of tiny writes scattered all over will tend to produce much higher write amplification than large sequential writes. So you'll get more actual wear to the drive from the 3TB of constant background churn than if you copied in 3TB of movies.

Those writes would have to be significantly smaller than the SSD's page (sector) size which is 512 bytes or 4 KiB. And would have to be written to different pages in rapid succession (to be flushed apart) - a standard serial write wouldn't trigger this even if it's 1 byte at a time, the OS FS cache would buffer it. It would have to be very misbehaving software or deliberate sabotage.

The logical block size presented by SSDs to the host system is 512 bytes or rarely 4kB. But the native page size of the flash memory itself is usually more like 16kB, and the erase block size is several MB at a minimum. Those larger sizes are why random writes (and especially random overwrites) can cause high write amplification within the SSD: because what looks like a series of single-sector writes to the host will at a minimum cause fragmentation within the SSD, and can easily cause large read-modify-write operations within the SSD.

Normally, SSDs and operating systems both use aggressive caching to combine writes. That's the only way a drive can turn in extremely high random write benchmark numbers. Consumer SSDs do this caching even though they do not have power loss protection capacitors to ensure that data cached in volatile SRAM will be flushed to the flash in an emergency. But it wouldn't be smart for the caching to wait forever for more writes to combine with a sub-page write, which is why I'd be concerned that a slow and steady trickle of write activity may be able to cause serious real write amplification.

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