9 ms·

>whatever failure damaged the SSD is statistically likely to compromise the reliability of the rest of the board Sorry, but how? That's just reads like BS. SS

>whatever failure damaged the SSD is statistically likely to compromise the reliability of the rest of the board Sorry, but how? That's just reads like BS. SSDs have limited lifespans due to the limited write cycles of the NAND chips. So no, what damages NAND does not damage the rest of the board. The more you write and swap to flash, the faster it wears out, taking your Macbook down with it when it dies. Granted, I expect the controller to keep moving your data around to the cells with the least ammount of wear and isolate the ones that have worn out, reducing your storage space and speed of the drive over time.

1123581321 5y ago
I think you are using old information. Any modern SSD should be good for a few hundred to several hundred TB and may reach a PB. It would be very hard to use a personal computer that heavily. Most people would take 20 years or more.
- ApolloRising 5y ago
  Video editors have workloads that can write a ton for each project in 4k and 8k resolutions, if its pro res even more. First thing they do is grab the largest fastest storage they can work off externally.
  - wtallis 5y ago
    That is a fairly write-heavy use case. But SSD endurance is measured in drive writes per day (over a typically 5-year warranty period). Rewriting the entire contents of your drive every workday for 2.5 years is only enough to put a typical consumer SSD out of warranty; actual failure due to write endurance will come much later.
  - filmgirlcw 5y ago
    Right -- but work externally is key here. Sure, you often have some stuff you'll do locally, but having external disk arrays is the name of the game if you're doing large volumes of video, not just because you want to be able to have a backup if your internal dies, but because lots of other people often touch your stuff and it just fits a workflow better to use fast networked storage when possible.
- sofixa 5y ago
  You're forgetting swap. Not to mention professionals in domains like photography, design, video, etc. who might chew through big files frequently.
  - 1123581321 5y ago
    Swap and other system activity is factored. Most heavy workloads wear other parts of the system as well. As another user pointed out, truly heavy storage and scratch system based workloads want to use large externals anyway, for other reasons.
  - rangoon626 5y ago
    Yes. Don't RAM-max at your own peril.
  - nottorp 5y ago
    > You're forgetting swap. 8 Gb should be enough for everyone :)
- KennyBlanken 5y ago
  That's not how SSD wear works because nobody completely writes to their SSD, erases it, and writes again. You can't wear-level against blocks that are in use, only blocks that are free. If every person I've helped socially and professionally is any indication, people keep their storage anywhere between 80% and 95% full. At 95% full, all your write cycles are focused on just 5% (plus spare provisioned blocks.) Think about how browsers consume all available memory and then readily push the system into using a lot of swap. I have to restart my browser regularly because of how much ram it uses even if I've closed every tab. Think about how whole-system file content indexing is the norm, and all the write operations that occur every time a file is added or updated. Think about how a lot of applications are just electron apps and they routinely update themselves. Think about all the filesystem metadata changes. Etc.
  - 1123581321 5y ago
    I did not say SSD wear works that way. All of that is factored into the usage I cited—-swap, system writes, etc. do not wear the drive as much as you appear to think for most users.
  - wtallis 5y ago
    > You can't wear-level against blocks that are in use, only blocks that are free. It only takes a bit of arithmetic to prove that this cannot possibly be true, or else all of those 95%-full drives would have long since failed, and QLC SSDs would have been a disaster and never would have been adopted by system OEMs that provide multi-year warranties. (And if it were true, then SSDs prior to TRIM wouldn't have been viable.) You can include static data in wear leveling, and all SSDs do. It does lead to some write amplification, but that's already factored in to a drive's endurance specs.
- rsync 5y ago
  "Any modern SSD should be good for a few hundred to several hundred TB and may reach a PB." Actually, even more than that - here are some examples:[1] Intel SSDSC2KB019TZ01 ("S4520") with 8.8 PB of lifetime writes Intel SSDSC2KB019T801 ("S4510") with 7.1 PB of lifetime writes Seagate ZA1920NM10001 ("Ironwolf[2] 110") with 3.5 PB of lifetime writes [2] Samsung MZ-76P2T0BW ("860 PRO") with 2.4 PB of lifetime writes [1] https://www.rsync.net/resources/notes/2021-q3-rsync.net_technotes.html https://www.rsync.net/resources/notes/2021-q3-rsync.net_tech... [2] https://twitter.com/rsyncnet/status/1402397708329967618 https://twitter.com/rsyncnet/status/1402397708329967618
  - wtallis 5y ago
    To be fair, those are unusually high-end products compared to typical consumer SSDs, and three out of four are enterprise drives where endurance is measured according to different criteria that inflates the number a bit further.
    - GhettoComputers 5y ago
      Those numbers aren't out of reach for consumer SSDs either.
- AdrianB1 5y ago
  I finished the life of a SSD in a single year of regular use; it was great to find it should not happen, but it did.
  - wtallis 5y ago
    What drive? What was the end of life behavior you observed? Catastrophic failure, or SMART data showing wearout?
    - nightski 5y ago
      Not the parent but I had this happen to me. It was a top of the line Samsung SSD at the time. Catastrophic failure. Was working fine then one day I rebooted and it never came back. I usually plan for failure of each drive every 2-3 years and buy them on Black Friday. But if that took out my entire 3.5k-4k m1 max laptop I'd be rather disappointed. It's $200 to replace a SSD.
      - wtallis 5y ago
        So, that failure mode makes it pretty much impossible to conclusively attribute it to wearing out the NAND write endurance. You probably hit a firmware bug or failure in a different SSD component, otherwise you would most likely have been getting warnings from your OS about impending drive failure based on SMART data. SSD wrote endurance is an unavoidable ticking time bomb. But it is nowhere near as unpredictable or imminent as many people assume. It's a failure mode that doesn't sneak up on you, and usually takes real effort to trigger. Other failure mechanisms are much more important.
      - magicalhippo 5y ago
        I've had two SSD's fail on, both were "here today, gone tomorrow" type failures without warning. Granted, been a while, but I do nightly full-disk backups due to the first such experience (so was well prepared for the second).
    - AdrianB1 5y ago
      Intel 535. I was showing some alerts and the Intel SSD tool said the remaining life was ~ 5%, then it got to zero so I replaced it.
xondono 5y ago
Limited write cycles will produce data corruption, but what the article explains is that Apple is using the Flash in M1 macs in a similar way to other ARM devices, that is, they have the firmware there. I don’t know how much time do you expect your mac to last, but write cycles on your firmware should not be much of a concern.
- exikyut 5y ago
  Right, but I get the impression that the firmware vies for space with the rest of / et al. Sooo that means the wear leveling had better be ahead of whatever lifetime writes you throw at the system, or...
  - sroussey 5y ago
    Easy to account for in drive firmware. Not to mention the file system if that were actually being used. Way back when, master boot records were duplicated at know locations for kinda similar reasons.
gruez 5y ago
that's true, but it's far more likely for the mainboard to get soaked/smashed than the NAND running out of write cycles.
wtallis 5y ago
In practice, exhausting NAND write endurance is usually not what causes SSDs to fail in the field. It is especially unlikely to be the underlying cause of unexpected and seemingly premature catastrophic SSD failure. Also, it is not possible for an SSD to decrease your usable storage space over time. That would break any partition table format or filesystem that expects an ordinary block device. It also wouldn't win you any significant increase unusable lifespan, because when your drive starts retiring large numbers of blocks, all of your blocks are on the verge of failure. (Though keep in mind that "failure" here is defined as "only able to retain data for one year" for consumer SSDs).
- phkahler 5y ago
  >> It also wouldn't win you any significant increase unusable lifespan, because when your drive starts retiring large numbers of blocks, all of your blocks are on the verge of failure. That's not true. Blocks degrade when written to. Most files are written once and read many times.
  - slaymaker1907 5y ago
    You're forgetting that SSDs use virtual addressing so writes are distributed relatively equally over the whole drive. Even data that is written once and never changed logically will probably move around on the SSD due to garbage collection. The virtualization algorithms are kept relatively secret, but I assume good SSDs will move full unchanged blocks around occasionally to distribute write load more equally on the physical blocks.
    - wtallis 5y ago
      Yep, wear leveling actually works. On some SSDs, there are SMART indicators to tell you the average, max and min block erase counts, so you can see for yourself that the erase counts are all about the same across the entire drive.
    - phkahler 5y ago
      >> I assume good SSDs will move full unchanged blocks around occasionally to distribute write load more equally on the physical blocks. I hadn't considered that. Make sense. Better to move never-changing data to blocks that are still good but not worn out so those available writes can be utilized.
Dylan16807 5y ago
How many SSDs have you worn out? I've never managed it.
- deleted 5y ago
  [deleted]
- KennyBlanken 5y ago
  Apple SSD module failures on portable Macs are quite common. A buddy has a computer repair shop and they do brisk business replacing them. Mine failed about 5 years in. SSDs are wear items. Especially when they're quite full, it is very easy to blow through spare writes and brick the drive.
  - floatingatoll 5y ago
    Did those modules fail readonly, and the SMART data showed that their write limit had been reached? Or did the entire module electronically fail, as distinct from the SSD "no more writes" case?
  - jbverschoor 5y ago
    There was a problem with some of the SSDs where they corrupt themselves on powerloss. That’s a totally different reason, and afaik, they should be using proper caps to let the controller write/flush their buffers. My last MacBook Pro was 7 years old, almost always full, and still works fine. Granted I’m not a video editor, but I had quite some write cycles.
- toast0 5y ago
  I've had hundreds of enterprise SSDs fail on my servers, but only a couple had any pre-failure indicators in SMART, including write volume which was pretty low. The post-failure indicator was almost consistently no longer visible through the disk controller. Failure rate was much less than enterprise spinning disks, but at least with the spinners failed, you could still see them and get most of the data off, if you needed to. And they had reliable pre-failure indications. TLDR: take regular backups and plan for storage to fail (which for soldered storage means plan to get a new device, I guess)
rvz 5y ago
> So no, what damages NAND does not damage the rest of the board. The more you write and swap to flash, the faster it wears out, taking your Macbook down with it when it dies. Except as explained by the parent, when the SSD dies on an Intel Mac it can be recovered via Internet Recovery via EFI. Only way to brick that it is to have a bad flash onto the EFI ROM. On Apple Silicon when the SSD dies, it cannot be recovered as the firmware is also on the SSD and remains bricked which that is that.
webmobdev 5y ago
> That's just reads like BS. Because it partly is. It's just a lame defence / justification of soldering SSD, RAM and other parts, the major advantage of which is to make modern electronics more complex, hard to repair and prevent upgrades (i.e. "planned obsolescence"). If SSDs were reliable beyond 5+ years, manufacturers would be highlighting that and even offering guarantees for such a period. (Hell, most RAM today come with "lifetime" guarantees, even though RAM modules too fail occasionally). The modular design for computer hardware was chosen for a practical reason - that hardware can, and do fail. While electronic manufacturing has advanced a lot, minimizing failure rates to a great extent, the pros of replaceable modules absolutely still outweigh any of the alternative hardware designs so far.
- bitwize 5y ago
  Except soldering everything on can give you HUGE performance boosts. Like, laptops come with soldered-on RAM that you can't get in a DIMM configuration because the soldered on stuff is so fast it needs a fast path to the CPU, which DIMM slots can't provide. And now with Apple building all system RAM directly into the chip die, it's just a whole new ballgame. So you can either go modular and have a slow PC, or you can have decent performance and just accept that everything is going to be soldered on and irreplaceable.
  - CelestialTeapot 5y ago
    Sorry, what? Citation please. The speed lost moving a DIMM from a 3cm path-to-CPU to a removable DIMM slot 6cm away is infinitesimal. You would not notice it.
    - wtallis 5y ago
      For laptops, soldered vs socketed DRAM is mostly about power, not performance. But it is true that soldering DRAM makes it possible to reach higher bus speeds than are practical to achieve through a DIMM slot; this is why GPUs don't have upgradable RAM.
      - 5y ago
jacquesm 5y ago
Heh, I wrote pretty much exactly the same thing, should have read all the comments first.

1123581321 5y ago

I think you are using old information. Any modern SSD should be good for a few hundred to several hundred TB and may reach a PB. It would be very hard to use a personal computer that heavily. Most people would take 20 years or more.

ApolloRising 5y ago
Video editors have workloads that can write a ton for each project in 4k and 8k resolutions, if its pro res even more. First thing they do is grab the largest fastest storage they can work off externally.
- wtallis 5y ago
  That is a fairly write-heavy use case. But SSD endurance is measured in drive writes per day (over a typically 5-year warranty period). Rewriting the entire contents of your drive every workday for 2.5 years is only enough to put a typical consumer SSD out of warranty; actual failure due to write endurance will come much later.
- filmgirlcw 5y ago
  Right -- but work externally is key here. Sure, you often have some stuff you'll do locally, but having external disk arrays is the name of the game if you're doing large volumes of video, not just because you want to be able to have a backup if your internal dies, but because lots of other people often touch your stuff and it just fits a workflow better to use fast networked storage when possible.
sofixa 5y ago
You're forgetting swap. Not to mention professionals in domains like photography, design, video, etc. who might chew through big files frequently.
- 1123581321 5y ago
  Swap and other system activity is factored. Most heavy workloads wear other parts of the system as well. As another user pointed out, truly heavy storage and scratch system based workloads want to use large externals anyway, for other reasons.
- rangoon626 5y ago
  Yes. Don't RAM-max at your own peril.
- nottorp 5y ago
  > You're forgetting swap. 8 Gb should be enough for everyone :)
KennyBlanken 5y ago
That's not how SSD wear works because nobody completely writes to their SSD, erases it, and writes again. You can't wear-level against blocks that are in use, only blocks that are free. If every person I've helped socially and professionally is any indication, people keep their storage anywhere between 80% and 95% full. At 95% full, all your write cycles are focused on just 5% (plus spare provisioned blocks.) Think about how browsers consume all available memory and then readily push the system into using a lot of swap. I have to restart my browser regularly because of how much ram it uses even if I've closed every tab. Think about how whole-system file content indexing is the norm, and all the write operations that occur every time a file is added or updated. Think about how a lot of applications are just electron apps and they routinely update themselves. Think about all the filesystem metadata changes. Etc.
- 1123581321 5y ago
  I did not say SSD wear works that way. All of that is factored into the usage I cited—-swap, system writes, etc. do not wear the drive as much as you appear to think for most users.
- wtallis 5y ago
  > You can't wear-level against blocks that are in use, only blocks that are free. It only takes a bit of arithmetic to prove that this cannot possibly be true, or else all of those 95%-full drives would have long since failed, and QLC SSDs would have been a disaster and never would have been adopted by system OEMs that provide multi-year warranties. (And if it were true, then SSDs prior to TRIM wouldn't have been viable.) You can include static data in wear leveling, and all SSDs do. It does lead to some write amplification, but that's already factored in to a drive's endurance specs.
rsync 5y ago
"Any modern SSD should be good for a few hundred to several hundred TB and may reach a PB." Actually, even more than that - here are some examples:[1] Intel SSDSC2KB019TZ01 ("S4520") with 8.8 PB of lifetime writes Intel SSDSC2KB019T801 ("S4510") with 7.1 PB of lifetime writes Seagate ZA1920NM10001 ("Ironwolf[2] 110") with 3.5 PB of lifetime writes [2] Samsung MZ-76P2T0BW ("860 PRO") with 2.4 PB of lifetime writes [1] https://www.rsync.net/resources/notes/2021-q3-rsync.net_technotes.html https://www.rsync.net/resources/notes/2021-q3-rsync.net_tech... [2] https://twitter.com/rsyncnet/status/1402397708329967618 https://twitter.com/rsyncnet/status/1402397708329967618
- wtallis 5y ago
  To be fair, those are unusually high-end products compared to typical consumer SSDs, and three out of four are enterprise drives where endurance is measured according to different criteria that inflates the number a bit further.
  - GhettoComputers 5y ago
    Those numbers aren't out of reach for consumer SSDs either.
AdrianB1 5y ago
I finished the life of a SSD in a single year of regular use; it was great to find it should not happen, but it did.
- wtallis 5y ago
  What drive? What was the end of life behavior you observed? Catastrophic failure, or SMART data showing wearout?
  - nightski 5y ago
    Not the parent but I had this happen to me. It was a top of the line Samsung SSD at the time. Catastrophic failure. Was working fine then one day I rebooted and it never came back. I usually plan for failure of each drive every 2-3 years and buy them on Black Friday. But if that took out my entire 3.5k-4k m1 max laptop I'd be rather disappointed. It's $200 to replace a SSD.
    - wtallis 5y ago
      So, that failure mode makes it pretty much impossible to conclusively attribute it to wearing out the NAND write endurance. You probably hit a firmware bug or failure in a different SSD component, otherwise you would most likely have been getting warnings from your OS about impending drive failure based on SMART data. SSD wrote endurance is an unavoidable ticking time bomb. But it is nowhere near as unpredictable or imminent as many people assume. It's a failure mode that doesn't sneak up on you, and usually takes real effort to trigger. Other failure mechanisms are much more important.
    - magicalhippo 5y ago
      I've had two SSD's fail on, both were "here today, gone tomorrow" type failures without warning. Granted, been a while, but I do nightly full-disk backups due to the first such experience (so was well prepared for the second).
  - AdrianB1 5y ago
    Intel 535. I was showing some alerts and the Intel SSD tool said the remaining life was ~ 5%, then it got to zero so I replaced it.

xondono 5y ago

Limited write cycles will produce data corruption, but what the article explains is that Apple is using the Flash in M1 macs in a similar way to other ARM devices, that is, they have the firmware there. I don’t know how much time do you expect your mac to last, but write cycles on your firmware should not be much of a concern.

exikyut 5y ago
Right, but I get the impression that the firmware vies for space with the rest of / et al. Sooo that means the wear leveling had better be ahead of whatever lifetime writes you throw at the system, or...
- sroussey 5y ago
  Easy to account for in drive firmware. Not to mention the file system if that were actually being used. Way back when, master boot records were duplicated at know locations for kinda similar reasons.

gruez 5y ago

that's true, but it's far more likely for the mainboard to get soaked/smashed than the NAND running out of write cycles.

wtallis 5y ago

In practice, exhausting NAND write endurance is usually not what causes SSDs to fail in the field. It is especially unlikely to be the underlying cause of unexpected and seemingly premature catastrophic SSD failure. Also, it is not possible for an SSD to decrease your usable storage space over time. That would break any partition table format or filesystem that expects an ordinary block device. It also wouldn't win you any significant increase unusable lifespan, because when your drive starts retiring large numbers of blocks, all of your blocks are on the verge of failure. (Though keep in mind that "failure" here is defined as "only able to retain data for one year" for consumer SSDs).

phkahler 5y ago
>> It also wouldn't win you any significant increase unusable lifespan, because when your drive starts retiring large numbers of blocks, all of your blocks are on the verge of failure. That's not true. Blocks degrade when written to. Most files are written once and read many times.
- slaymaker1907 5y ago
  You're forgetting that SSDs use virtual addressing so writes are distributed relatively equally over the whole drive. Even data that is written once and never changed logically will probably move around on the SSD due to garbage collection. The virtualization algorithms are kept relatively secret, but I assume good SSDs will move full unchanged blocks around occasionally to distribute write load more equally on the physical blocks.
  - wtallis 5y ago
    Yep, wear leveling actually works. On some SSDs, there are SMART indicators to tell you the average, max and min block erase counts, so you can see for yourself that the erase counts are all about the same across the entire drive.
  - phkahler 5y ago
    >> I assume good SSDs will move full unchanged blocks around occasionally to distribute write load more equally on the physical blocks. I hadn't considered that. Make sense. Better to move never-changing data to blocks that are still good but not worn out so those available writes can be utilized.

Dylan16807 5y ago

How many SSDs have you worn out? I've never managed it.

deleted 5y ago
[deleted]
KennyBlanken 5y ago
Apple SSD module failures on portable Macs are quite common. A buddy has a computer repair shop and they do brisk business replacing them. Mine failed about 5 years in. SSDs are wear items. Especially when they're quite full, it is very easy to blow through spare writes and brick the drive.
- floatingatoll 5y ago
  Did those modules fail readonly, and the SMART data showed that their write limit had been reached? Or did the entire module electronically fail, as distinct from the SSD "no more writes" case?
- jbverschoor 5y ago
  There was a problem with some of the SSDs where they corrupt themselves on powerloss. That’s a totally different reason, and afaik, they should be using proper caps to let the controller write/flush their buffers. My last MacBook Pro was 7 years old, almost always full, and still works fine. Granted I’m not a video editor, but I had quite some write cycles.
toast0 5y ago
I've had hundreds of enterprise SSDs fail on my servers, but only a couple had any pre-failure indicators in SMART, including write volume which was pretty low. The post-failure indicator was almost consistently no longer visible through the disk controller. Failure rate was much less than enterprise spinning disks, but at least with the spinners failed, you could still see them and get most of the data off, if you needed to. And they had reliable pre-failure indications. TLDR: take regular backups and plan for storage to fail (which for soldered storage means plan to get a new device, I guess)

rvz 5y ago

> So no, what damages NAND does not damage the rest of the board. The more you write and swap to flash, the faster it wears out, taking your Macbook down with it when it dies. Except as explained by the parent, when the SSD dies on an Intel Mac it can be recovered via Internet Recovery via EFI. Only way to brick that it is to have a bad flash onto the EFI ROM. On Apple Silicon when the SSD dies, it cannot be recovered as the firmware is also on the SSD and remains bricked which that is that.

webmobdev 5y ago

> That's just reads like BS. Because it partly is. It's just a lame defence / justification of soldering SSD, RAM and other parts, the major advantage of which is to make modern electronics more complex, hard to repair and prevent upgrades (i.e. "planned obsolescence"). If SSDs were reliable beyond 5+ years, manufacturers would be highlighting that and even offering guarantees for such a period. (Hell, most RAM today come with "lifetime" guarantees, even though RAM modules too fail occasionally). The modular design for computer hardware was chosen for a practical reason - that hardware can, and do fail. While electronic manufacturing has advanced a lot, minimizing failure rates to a great extent, the pros of replaceable modules absolutely still outweigh any of the alternative hardware designs so far.

bitwize 5y ago
Except soldering everything on can give you HUGE performance boosts. Like, laptops come with soldered-on RAM that you can't get in a DIMM configuration because the soldered on stuff is so fast it needs a fast path to the CPU, which DIMM slots can't provide. And now with Apple building all system RAM directly into the chip die, it's just a whole new ballgame. So you can either go modular and have a slow PC, or you can have decent performance and just accept that everything is going to be soldered on and irreplaceable.
- CelestialTeapot 5y ago
  Sorry, what? Citation please. The speed lost moving a DIMM from a 3cm path-to-CPU to a removable DIMM slot 6cm away is infinitesimal. You would not notice it.
  - wtallis 5y ago
    For laptops, soldered vs socketed DRAM is mostly about power, not performance. But it is true that soldering DRAM makes it possible to reach higher bus speeds than are practical to achieve through a DIMM slot; this is why GPUs don't have upgradable RAM.
    - 5y ago

jacquesm 5y ago

Heh, I wrote pretty much exactly the same thing, should have read all the comments first.