ssd swap - high usage of Terabytes Written

[ValSalva]

Yup, I get that on my M1 Mac mini all the time. It’s a feature.
Also, I have to shut down the M1 twice in a row, the second time without logging in.

I consider these minor annoyances and not deal breakers.

I wonder how widespread this is. What you did is exactly what I did with not logging in and then shutting down. There was a kernel panic report upon that automatic restart but no one from Apple knew what it was because it was too nonspecific. I emailed the developer of Keyboard Maestro because it seemed to start after installing that. He said that KM cannot cause kernel panics. He thought a process was hanging at shutdown. I never tried manually force quitting processes in Activity Monitor but maybe should have to see which one it was.

I guess if there is no data loss then it's not a deal-breaker. It's clearly software. Maybe a future update will fix this or maybe it won't be present in macOS 13.

 

[Maximara]

The numbers quoted by @Fomalhaut are for an Intel 16" MacBook Pro. I don't know who makes the SSD controller for that machine. If it is from the T2 then it is on Apple if that estimate is wrong. The same with the M1 Macs. If the percentage used from the SMART Health block is wrong, Apple is responsible since they made the NVMe controller.

View attachment 1741601
Anyway, most people here are more worried about the TBW number than the percentage used number. You can write to your SSD and use the smartctl command before and after and see that the TBW value increments correctly. Try it yourself.

I am using an old platter drive Mac so TBW tests are useless for me. Also smartmontools' page on NVMe support in the different OS says nothing about there being a hardware issue regarding the T2 and that chip has been in Macs since 2018. As for the TBW value 'incrementing correctly' there are two values: the raw value and the percentage. If things are working correctly one can black box the whole SSD and come up with a TBW and se if that match what the program is telling one.

What I found when I checked my M1 MacBook Air SSD brings a little reality back into the situation.

 

[pcharlesmorphy]

Another display of erratic behavior on the part of Big Sur.
A 38 Mb Word document which I was retouching for submission, about 12-14 image captures and 22 pages. For 40 minutes open, then I closed it but left Word open, after 1h, I went to look at the Activity Monitor to see 5Gb of writing by Word!!!!
It is quite clear that something is not working as it should.
After 3 hours since this image, only 2Gb of writing with the same programs open except Word.

 

[Gustavo Carvalh]

On the first day, processes associated with iCloud (bird and some others) wrote 1TB to the disk on my M1 MBA in a few hours. I only have 20Gb in my iCloud drive. At first I thought it could be some glitch when downloading files, but further inspection revealed that nothing was using the network. Less than 1Gb had been downloaded so far. I turned iCloud off and on again and the same thing happened. Cleared some unused files from it using another Mac and turned it on again. This time, it worked. iCloud drive is on and I see very little disk usage. All this happened at the first boot, before I even downloaded third party apps.

 

[Maximara]

Another display of erratic behavior on the part of Big Sur.
A 38 Mb Word document which I was retouching for submission, about 12-14 image captures and 22 pages. For 40 minutes open, then I closed it but left Word open, after 1h, I went to look at the Activity Monitor to see 5Gb of writing by Word!!!!
It is quite clear that something is not working as it should.
After 3 hours since this image, only 2Gb of writing with the same programs open except Word.

But that looks like it is not Big Sur's issue but Word's. It;s like the joke Mac users had back in the late 1980s.

User: I have a problem with my Mac.
IT: Oh what is it?
User: Well I am using Microsoft..."
IT: Stop right there. That is your problem...using Microsoft anything.

LibreOffice does much the same thing as Office and can import Word documents. Does this file have the same memory issues in LibreOffice as in Word? If so then things shift toward the OS but if not then the problem is Microsoft not knowing how to program not Apple's OS having a bug.

 

[jdb8167]

I am using an old platter drive Mac so TBW tests are useless for me. Also smartmontools' page on NVMe support in the different OS says nothing about there being a hardware issue regarding the T2 and that chip has been in Macs since 2018. As for the TBW value 'incrementing correctly' there are two values: the raw value and the percentage. If things are working correctly one can black box the whole SSD and come up with a TBW and se if that match what the program is telling one.

What I found when I checked my M1 MacBook Air SSD brings a little reality back into the situation.

Yes. You can write a fixed but large amount of data to the drive and then look at data units written and see that the amount written is the same. It is a very easy test that literally anyone with an NVMe Mac can do. Create a large blank read/write disk image using the Disk Utility. This creates a file of the size requested. Create a 100 GB image. This should increase the data units written reported by smartctl by just under 200,000.

I'm not sure what the ZDNet article proves or disproves. We already know that most people aren't affected by this problem but if you are, it could be catastrophic.

 

[Baff]

I'm not sure what the ZDNet article proves or disproves. We already know that most people aren't affected by this problem but if you are, it could be catastrophic.

Yeah, reading it was a complete waste of time. To save everyone else time, just read this sentence which captures the gist of the whole article: "The excessive write behavior on M1 Macs isn't universal, based on my sample size of 1."

 

[IceStormNG]

Could it be that it's also related to the automatic APFS snapshots? They get created and deleted every hour depending on disk usage. And they can cause quite some disk writes depending on how much changed on the filesystem.

I don't have an M1 machine, but my 16" MBP does way more writes than my 2013 Late did. My 2013 had 40TBW in 7 years. My 16" has 20TBW in half a year. Even though I do more or less the same stuff and the 16" has double the RAM.

 

[pshufd]

Could it be that it's also related to the automatic APFS snapshots? They get created and deleted every hour depending on disk usage. And they can cause quite some disk writes depending on how much changed on the filesystem.

I don't have an M1 machine, but my 16" MBP does way more writes than my 2013 Late did. My 2013 had 40TBW in 7 years. My 16" has 20TBW in half a year. Even though I do more or less the same stuff and the 16" has double the RAM.

I'm running Mojave on my MacBook Pros and don't see all of these writes.

My daughter is running an Air 16/1 and it's not doing a lot of writes. But she's only using 7 GB of RAM.

So there is likely some combination of things. My guess is that the vast majority of M1 users aren't seeing this.

 

[Baff]

My guess is that the vast majority of M1 users aren't seeing this.

Agreed, but I think it is easily repeatable for anyone who has an M1, if they really want to take the 10 minutes to do so.

 

[Argon_]

I'm running Mojave on my MacBook Pros and don't see all of these writes.

My daughter is running an Air 16/1 and it's not doing a lot of writes. But she's only using 7 GB of RAM.

So there is likely some combination of things. My guess is that the vast majority of M1 users aren't seeing this.

I'm suspicious of the Time Machine local backups in this problem. Does her machine have them enabled?

 

[Baff]

I'm suspicious of the Time Machine local backups in this problem. Does her machine have them enabled?

Time Machine may well exacerbate the problem, but it is not the source of the problem (unless this is actually a bunch of unrelated problems that all cause massive disk writes). I and at least one other person only run TM manually. I haven't run it since getting this M1 Mini last week.

I can easily trigger massive writes by opening 100 tabs in Safari, but I doubt that the issue is actually with Safari.

It seems to me that if the memory gets too overloaded, it triggers the constant writes. When my swap gets up over about 4GB, the writes start (~10GB/ hour). Up around 7GB swap, they start going really crazy (~50GB/hour).

Some swear up and down that it can't possibly be the Swap. Maybe they are right. Maybe it is the Cache or some other aspect of the memory management.

For anyone who has an M1 and thinks this is just some Intel conspiracy:
1. Open Activity Monitor, and switch to the Disk tab. Sort by Bytes Written.
2. Open Safari.
3. Open tabs for your favorite 200 websites (actual busy websites (NYT, MacRumors, etc. etc), not just simple text files). If your bookmarks are sorted into folders, at the bottom of the folder is "Open in New Tabs" which will quickly open every link in that folder.
4. Quickly scroll to the bottom of every website to make sure it is fully active.
5. Watch Activity Monitor. Disk and Memory tabs. At the bottom of the Disk tab it shows Data Written. You can also click on IO and change that to Data to watch the graph.

 

[Forti]

I'm suspicious of the Time Machine local backups in this problem. Does her machine have them enabled?

I'm not using time machine at all. Either manually or automatically. It's turned off all the time.

 

[handheldgames]

I'm not using time machine at all. Either manually or automatically. It's turned off all the time.

OP.. Not sure if this was brought up.... Perhaps the disk usage can be explained in two words: VIRTUAL MEMORY.

Has anyone tested disk usage on an Intel Mac with 8GB/16GB RAM with the identical workflow that's exhibiting the issues on the M1s?

 

[wirtandi]

Still cannot believe Apple has not said anything about this. Every single day I check if there is anything from them but no, nothing at all.

I need to buy a new laptop 😞

 

[pshufd]

I'm suspicious of the Time Machine local backups in this problem. Does her machine have them enabled?

No, she does everything in the cloud. But I have Time Machine on my systems but backups don't take that long so probably not a big contributor.

 

[Forti]

OP.. Not sure if this was brought up.... Perhaps the disk usage can be explained in two words: VIRTUAL MEMORY.

Has anyone tested disk usage on an Intel Mac with 8GB/16GB RAM with the identical workflow that's exhibiting the issues on the M1s?

Yes, I have MBP intel 2018 13" 16/256. I was using it for over 2 years and 2-4 months. Along with Big Sur for couple of months at least.
And then I have the Mac mini m1 16/256.

I'm using both machines for the same tasks, same workflow, same tools. Even the same projects for last couple of months. Daily job.

Like in my first post in this topic:

MBP intel - 47.5 TBW after those 2 years and 2-4 months usage
Mac mini m1 - today I have 5.82 TB and it's been ~~ 1 month. I got it sometime between 7-9 January if I'm correct. ( I would need to check the invoice for that)

so let's do same math - after 2 years and 2-4 months I can have ~~150-180 TBW compared to 47.5 TBW on MacBook Pro.

I know this is NOT MUCH and many people around here and on twitter are in a lot worse situation. And some people doesn't have this is at all.

I know it can be because of the way people are using those machines - some are doing photo / video editing, others just using safari, others programming, sound editing maybe. Etc etc etc.

but still - in my case - comparing to intel Mac I can see the difference.

It would be nice if Apple could just say "Hey folks, this is ok, don't worry. The SSD should last for years and in case it will die you still have the warranty" - that would kinda-ok in my opinion. Or anything.

 

[abhi182]

Yes, I have MBP intel 2018 13" 16/256. I was using it for over 2 years and 2-4 months. Along with Big Sur for couple of months at least.
And then I have the Mac mini m1 16/256.

I'm using both machines for the same tasks, same workflow, same tools. Even the same projects for last couple of months. Daily job.

Like in my first post in this topic:

MBP intel - 47.5 TBW after those 2 years and 2-4 months usage
Mac mini m1 - today I have 5.82 TB and it's been ~~ 1 month. I got it sometime between 7-9 January if I'm correct. ( I would need to check the invoice for that)

so let's do same math - after 2 years and 2-4 months I can have ~~150-180 TBW compared to 47.5 TBW on MacBook Pro.

I know this is NOT MUCH and many people around here and on twitter are in a lot worse situation. And some people doesn't have this is at all.

I know it can be because of the way people are using those machines - some are doing photo / video editing, others just using safari, others programming, sound editing maybe. Etc etc etc.

but still - in my case - comparing to intel Mac I can see the difference.

It would be nice if Apple could just say "Hey folks, this is ok, don't worry. The SSD should last for years and in case it will die you still have the warranty" - that would kinda-ok in my opinion. Or anything.

Another way to look at it is that you will have a lot of writes after a fresh OS install / indexing (as would have happened at the onset ) , a fair amount after every update and a relatively small incremental count for regular usage.

I have noticed approx 50GB incremental writes on mine per day for reg usage - if you ignore the initial count.
While your usage patterns will be very different from mine but for the sake of comparisons, let me just Extrapolate it to your scenario - so 50Gb/day X 2 years = 35.6TB
Add the current count and you are in the same ballpark figure as your Intel MBP


I kinda wish I'd have taken the stats off my old Intel MBP before selling it - would have made for an interesting comparison ..
Would be interested in seeing your daily increments if you can simply post back the Data written value from activity monitor (disk tab) and the total uptime (terminal command: uptime )

 

[Baff]

Has anyone tested disk usage on an Intel Mac with 8GB/16GB RAM with the identical workflow that's exhibiting the issues on the M1s?

I copied everything from my Intel Mini (16GB, 1TB fusion drive) over to this M1 Mini (16GB, 1TB SSD). My Intel mini has 90TB written over 6 years (average 1.25TB/month) with similar but more usage than I am doing now on the M1. I did a fair amount of gaming on the Intel, I have done very little on the M1 so far.

 

[Forti]

Another way to look at it is that you will have a lot of writes after a fresh OS install / indexing (as would have happened at the onset ) , a fair amount after every update and a relatively small incremental count for regular usage.

I have noticed approx 50GB incremental writes on mine per day for reg usage - if you ignore the initial count.
While your usage patterns will be very different from mine but for the sake of comparisons, let me just Extrapolate it to your scenario - so 50Gb/day X 2 years = 35.6TB
Add the current count and you are in the same ballpark figure as your Intel MBP


I kinda wish I'd have taken the stats off my old Intel MBP before selling it - would have made for an interesting comparison ..
Would be interested in seeing your daily increments if you can simply post back the Data written value from activity monitor (disk tab) and the total uptime (terminal command: uptime )

I'm checking every single day the usage with smartctl command line tool. Even in sleep mode (I made a post with more data a few pages ago) I saw a few dozen GB written

With daily usage I have ~~300 GBW daily (I learned to logout out for nights - it does save something and there are days when I'm not using computer at all)

When I created this thread I wrote this:

Mac mini m1 - 0.9 TBW (after 8 days).

so as much as I would like to think that you are right - unfortunately I have to say that I don't think so

 

[abhi182]

I'm checking every single day the usage with smartctl command line tool. Even in sleep mode (I made a post with more data a few pages ago) I saw a few dozen GB written

With daily usage I have ~~300 GBW daily (I learned to logout out for nights - it does save something and there are days when I'm not using computer at all)

When I created this thread I wrote this:



so as much as I would like to think that you are right - unfortunately I have to say that I don't think so

Damn - Thats really odd.
300 Gig a day is quite a bit and is more than 1 DWPD on the 250 GB variant

I guess I will consider myself lucky (for now) but sure hope that apple comes out with a clarification (or a fix ) soon.
There is really no reason for an OS to thrash the disk so much

 

[antwormcity]

I had that problem too. I returned my M1 MBP because I thought it was defective and it was still in the holiday return window. Mine would also do the following: I'd use the Mac for some work. I'd quit every app. Then I'd shut it down. After seemingly being shut down, it would spontaneously reboot five to ten seconds later. Upon that reboot it would display the error saying that it was not properly shut down. Bizarre.

I have been caught by surprise at times in a similar fashion. I'd close all applications before a systematic shutdown from the menu while using an external display. When I open the lid to start M1 MB Air again and login, the old applications will all get launched back and the dreaded error message of improper shutdown. Single connection USB-C to a prosumer grade color reference monitor with a good power supply unit.

Yup, I get that on my M1 Mac mini all the time. It’s a feature.
Also, I have to shut down the M1 twice in a row, the second time without logging in.

I consider these minor annoyances and not deal breakers.

Yeah the point is they better test those things out - there are many "Operating Systems" Comp Science geniuses including PhDs and Postdocs in Apple to never let that leave the release gate.

Yup, that’s my assumption.
I have 2 TB3 docks attached to the Thunderbolt / USB 4 ports.
Both or one from OWC, in the latter case one from CalDigit.
Maybe that has an influence on the shutdown issue.
I wonder how many other M1 users have a similar experience though?

I can confirm on mine - running on 90% battery charge no external connections or peripherals whatsoever, sitting on my sofa as portable as a laptop gets like an iPad - a restart results in the same error.

 

[Isamilis]

Could it be that it's also related to the automatic APFS snapshots? They get created and deleted every hour depending on disk usage. And they can cause quite some disk writes depending on how much changed on the filesystem.

I don't have an M1 machine, but my 16" MBP does way more writes than my 2013 Late did. My 2013 had 40TBW in 7 years. My 16" has 20TBW in half a year. Even though I do more or less the same stuff and the 16" has double the RAM.

My air 20 using Catalina and has 4TB TBW for 6 months.

 

[Fomalhaut]

I don’t doubt that some people are seeing strange write patterns (but not necessarily wrong), but 4TB in 2 months sounds perfectly normal to me.
Based on this usage, your son’s SSD will last for well over 10 years. Maybe double that or more.

This thread seems to be losing perspective.

We need to be looking at power-up hours not date ranges. In 2 months of work use (with some personal use) I would probably use the computer for over 400 hours. That would only be 5GB / hour if 4TB was written. A pretty normal figure, I think. If it's only 20 hours of use, then it's more concerning (100GB/hour), but would still provide at least 10 years usage. It's not ideal, but it's less alarming.

This is not an M1 or BigSur only issue. My MBP16 (32GB) with Catalina wrote 170TB with 1550 hours uptime, over a period of 15 months. The fact smartctl only show 2% "wear" makes me feel a bit better. Whether this is accurate or linear, I don't know.

I would like Apple to issue a technical note on this subject though.

 

[Wando64]

Yes, I have MBP intel 2018 13" 16/256. I was using it for over 2 years and 2-4 months. Along with Big Sur for couple of months at least.
...
MBP intel - 47.5 TBW after those 2 years and 2-4 months usage

Never mind the last two years. That’s irrelevant.
You need to compare like with like, so what happened on the Intel machine since you installed Big Sur?