ssd swap - high usage of Terabytes Written

[thadoggfather]

To whoever said that M1 does some "magic" and much RAM isn't needed: You have no clue what you're talking about.


Now you can roast me for saying that the M1's RAM is not so magic as some people tell you...

I won't say ram utilization is 'magic', you won't hear those words come out of my mouth, but your theory doesn't hold up because I have M1/8GB base Air

29 days uptime
268gb - W, 716gb - R

so its clearly not affecting everyone, since some people with 16GB are in way worse shape

im not wanting to reboot or power down, in the name of science

 

[gank41]

That is exactly part of my point.
The other part is that different OSs behave in different way, especially after the file system has radically changed to APFS.

I see people saying "my old Mac xxx has done some many TBW in so many years, whereas my new M1 has done so many is so many weeks".
That type of comparison is pointless and doesn't prove anything. It doesn't compare like with like.
Different OS, different file system, different SSD generation.

I checked my 2015 MBP (macOS 11.2.3 / APFS with a swapped out 2TB OWC drive), 120 TBW over 12,272 Power On Hours. Pretty normal/good.
I just erased/restored my M1 MBP 16GB/2TB via Apple Configurator 2 the other day. Before the erase/restore I was at 25.2 TBW (692 Power On Hours), and now I'm at 28.3 TBW (731 Power On Hours).

When I initially checked after finding this forum on the topic back on Feb 23, I was at 22.7 TBW (601 Power On Hours). I think we were on macOS 11.1 at the time? If reinstalling the entire OS only adds a couple TB for me (I've got about 1½ TB used up on my 2 TB drive, so.. yeah), where the heck did the initial 20+ TB come from? Is my math just that off? Nov 27 is when I got it.


EDIT:: Yes, my math is off. Does that equal out to be roughly 250 GB of write per day since end of Nov? From what I just checked, it looks like I'm averaging about a ¼ of a TB per day. Which makes perfect sense to me.

 

[VitoBotta]

Well, it's pretty easy to write that much with swap. If your apps are busy, the swap has to be paged-in and out constantly.

To whoever said that M1 does some "magic" and much RAM isn't needed: You have no clue what you're talking about.

Yes: The unified memory is fast and has performance advantages especially for GPU stuff. But it has no effect on quantity. Fast RAM is good. But the most important thing about RAM is that you have enough to fit all your applications and their data into it.


The reason why a 8GB M1 performs similar to a 16GB Intel is, that the M1 machines use much faster SSDs so swap has less performance impact. But it still shreds the SSD if you constantly use too much swap.

If all your apps you use simultaneously need more than, say, 8GB RAM, then buying a Mac with 8GB was a bad choice.


I'm pretty sure, that most of the disk writes come from swap on machines with not enough RAM for all the Apps that are used. Especially "modern" Apps are often Electron based. Those app easily eat 1-2GB of RAM (apps like Discord, VS Code, Slack, WhatsApp for Mac, ...).
The OS also needs RAM for its services and also for caches and buffers. macOS wants at least 4GB RAM for itself.


Yeah, your SSD will be shredded by the swap.


In your special case: 155TB / 73 days = 2.12TB/d
Which is pretty crazy though. It will take you 470 days to write 1PB of data. So at that rate your SSD might last 2, maybe 3 years depending on capactiy.

You also have to take wear leveling and write amplification into account. The fuller your SSD is the more writes it will actually do to the NAND. Even if you write just 1GB of data, your SSD might actually writes 4GB of data, because it has to move data before.



Now you can roast me for saying that the M1's RAM is not so magic as some people tell you...

The weird thing is that some people are doing heavy video editing and don't see those massive writes. Besides browser, email client and a few chat clients, I always have a text editor, the terminal, Docker and no big apps really. Most of the apps are native too. So I don't understand what's happening in my case.

My Mac is a mini with 16 GB of RAM and 256 GB of storage, filled around half (I keep my data on an external SSD).

 

[IceStormNG]

I won't say ram utilization is 'magic', you won't hear those words come out of my mouth, but your theory doesn't hold up because I have M1/8GB base Air

29 days uptime
268gb - W, 716gb - R

so its clearly not affecting everyone, since some people with 16GB are in way worse shape

im not wanting to reboot or power down, in the name of science

Well, this comes down to your usage. If you don't need more RAM, then 8GB are fine. If someone with 16GB RAM actually needs 32GB RAM for their work, then they will use a lot of swap.

Not to forget that macOS preemptively swaps even if you have enough RAM. But that is usually negligible on SSD wear.

 

[gank41]

I won't say ram utilization is 'magic', you won't hear those words come out of my mouth, but your theory doesn't hold up because I have M1/8GB base Air

29 days uptime
268gb - W, 716gb - R

so its clearly not affecting everyone, since some people with 16GB are in way worse shape

im not wanting to reboot or power down, in the name of science

Was it you that said you were sticking with only AS apps and trying not to install Rosetta 2? I'm sure this issue as a whole is a combination of things. I'm just curious if maybe the App Translation is a part of it. In my case, using 2 VMs with the Parallels Tech Preview, along with a handful of regularly used apps translated via Rosetta 2..

 

[thadoggfather]

Was it you that said you were sticking with only AS apps and trying not to install Rosetta 2? I'm sure this issue as a whole is a combination of things. I'm just curious if maybe the App Translation is a part of it. In my case, using 2 VMs with the Parallels Tech Preview, along with a handful of regularly used apps translated via Rosetta 2..

no VMs and no translated apps correct

if I come across an app I have to have that’s intel. I’ll certainly try it and keep an eye Obut

I was almost all apple silicon apps except my ad blocker but I “fixed” that with AS iWiper quick

I’m also still on 11.2.1

BT was fixed in 11.2, and the fix for sudo but in .1 interested me but haven’t updated since

the dock issue isn’t one for me since I don’t use third party docks (part of .2) and haven’t really kept up with the .3 fix

 

[IceStormNG]

The weird thing is that some people are doing heavy video editing and don't see those massive writes.

Final cut for example is pretty light on RAM in most cases. IDE's like Android Studio are way worse on RAM usage.

But I'm pretty sure that "not enough" RAM has something to do with that. I put that in quotes as macOS sometimes does weird decisions of what to leave in RAM and what to page out.

 

[pshufd]

I agree that "not enough" RAM is an issue. It's not clear to me if this is an M1 problem, a software problem, an operating system problem or interactions in certain environments. What I do know is that I have not seen this in any of the Macs that I've checked in our household and I have not heard about it other than here, in YouTube videos talking about it and as a concern in r/Mac. That is I think that it's fairly uncommon. But a lot of people here do far more with their systems than the typical user.

I specifically size my systems so that they don't swap but this is much harder to do with soldered in RAM or RAM on the SoC. I do hope that the iMac has user-installable RAM. I'm pretty sure that the Mac Pro will when it gets the AS treatment.

 

[Baff]

Comparing the swap data of a 5+ years old Mac and MacOS (or OSX as it was called then) with a modern machine with the latest version of MacOS doesn’t make any sense to me.

Uh, so what does make sense to you???
We have also compared to plenty of people here who have reported low writes. Does that make sense to you?
We have compared high memory load to low memory load on the same machines. Does that make sense to you?

Feel free to run the extremely simple experiment that I detailed on the previous page and tell us the results. Then you can make any comparisons you like.

FYI: Multiple people in this thread asked if we saw similar write levels on our previous macs with similar usage.

 

[badsimian]

I agree that "not enough" RAM is an issue. It's not clear to me if this is an M1 problem, a software problem, an operating system problem or interactions in certain environments. What I do know is that I have not seen this in any of the Macs that I've checked in our household and I have not heard about it other than here, in YouTube videos talking about it and as a concern in r/Mac. That is I think that it's fairly uncommon. But a lot of people here do far more with their systems than the typical user.

I specifically size my systems so that they don't swap but this is much harder to do with soldered in RAM or RAM on the SoC. I do hope that the iMac has user-installable RAM. I'm pretty sure that the Mac Pro will when it gets the AS treatment.

I have a 16GB model but actually use it fairly lightly. if I look at activity monitor and/or iStats, I usually have at least 4GB of actual free memory above and beyond wired/active/compressed. I use Citrix workspace, various browsers and Spotify, VSCode (mostly text editing) yet I am writing approx 100-200GB/day and currently at 16.3TBW.

It can't just be down to memory pressure.

 

[Wando64]

Uh, so what does make sense to you???
We have also compared to plenty of people here who have reported low writes. Does that make sense to you?
We have compared high memory load to low memory load on the same machines. Does that make sense to you?

Feel free to run the extremely simple experiment that I detailed on the previous page and tell us the results. Then you can make any comparisons you like.

FYI: Multiple people in this thread asked if we saw similar write levels on our previous macs with similar usage.

Tone it down buddy.
Your response makes me think you believe I am belittling the problem.
Far from it, I'd like to see this issue resolved as much as everyone else.

I thought I made my point pretty clear.
What makes sense to me is to compare like with like. Only then one can begin to attempt to establish where is the origin of the problem.
Right now all I see is a thread in the Apple Silicon forum, when we don't know if the problem (if it is a problem) is caused by the hardware architecture (looks like it isn't), by the OS version or by the file system.
Comparing 2021 APFS, Big Sur swap data with 2016 HFS, Sierra swap data, as some have done, is pointless.
So unless your "previous macs with similar usage" also run Big Sur, I think you are wasting time making comparisons if your purpose is to establish whether this is a specific M1 issue.

You are free to believe otherwise and that's fine with me. Let's keep it courteous please.

 

[daverdfw]

ok I tried something new, and so far it seems to have positive results. I added my entire drive as an exclusion to time machine, and in 18 hours kernel_task has only written 44GB total. Thats a dramatic decrease it would have been in the several hundreds by now. Curious for other folks to try it and see what happens.

 

[k-hawinkler]

ok SO I tried something new, and so far it seems to have positive results. I added my entire drive as an exclusion to time machine, and in 18 hours kernel_task has only written 44GB total. Thats a dramatic decrease it would have been in the several hundreds by now. Curious for other folks to try it and see what happens.

I use Time Machine in manual mode when I deem it necessary.
Problem solved, at least that one.

 

[Never mind]

.

 

[TheSynchronizer]

ok SO I tried something new, and so far it seems to have positive results. I added my entire drive as an exclusion to time machine, and in 18 hours kernel_task has only written 44GB total. Thats a dramatic decrease it would have been in the several hundreds by now. Curious for other folks to try it and see what happens.

Just tried the same, and will report back with results if my writes decrease

 

[Dockland]

Well, it's pretty easy to write that much with swap. If your apps are busy, the swap has to be paged-in and out constantly.

To whoever said that M1 does some "magic" and much RAM isn't needed: You have no clue what you're talking about.

Yes: The unified memory is fast and has performance advantages especially for GPU stuff. But it has no effect on quantity. Fast RAM is good. But the most important thing about RAM is that you have enough to fit all your applications and their data into it.


The reason why a 8GB M1 performs similar to a 16GB Intel is, that the M1 machines use much faster SSDs so swap has less performance impact. But it still shreds the SSD if you constantly use too much swap.

If all your apps you use simultaneously need more than, say, 8GB RAM, then buying a Mac with 8GB was a bad choice.


I'm pretty sure, that most of the disk writes come from swap on machines with not enough RAM for all the Apps that are used. Especially "modern" Apps are often Electron based. Those app easily eat 1-2GB of RAM (apps like Discord, VS Code, Slack, WhatsApp for Mac, ...).
The OS also needs RAM for its services and also for caches and buffers. macOS wants at least 4GB RAM for itself.


Yeah, your SSD will be shredded by the swap.


In your special case: 155TB / 73 days = 2.12TB/d
Which is pretty crazy though. It will take you 470 days to write 1PB of data. So at that rate your SSD might last 2, maybe 3 years depending on capactiy.

You also have to take wear leveling and write amplification into account. The fuller your SSD is the more writes it will actually do to the NAND. Even if you write just 1GB of data, your SSD might actually writes 4GB of data, because it has to move data before.



Now you can roast me for saying that the M1's RAM is not so magic as some people tell you...

Agree, otherwise they can stick with max 16 GB forever in upcoming iMacs/Pro-desktop models and whatever

Will not happen, I assume

 

[macbrush]

I just bought a brand new 16GB M1 a few days ago, checked when I first start it up, written about 400GB already, and I watch it go up like 10GB a min, while I was doing nothing. Mind you that I was consciously not opening up too many apps at once for a few days, I used it like it was System 7, I hit cmd-q all the time.

But then after updated to 11.2.3, everything just gone back to normal, now it just stays at 900GB written pretty much all day long for me.

 

[Dockland]

I just bought a brand new 16GB M1 a few days ago, checked when I first start it up, written about 400GB already, and I watch it go up like 10GB a min, while I was doing nothing. Mind you that I was consciously not opening up too many apps at once for a few days, I used it like it was System 7, I hit cmd-q all the time.

But then after updated to 11.2.3, everything just gone back to normal, now it just stays at 900GB written pretty much all day long for me.

My was around 400GB out of the box as well. Sync of iCloud took a part for me. Now I'm averaging 10-15 GB/day (4-8h uptime per day)

 

[daverdfw]

I use Time Machine in manual mode when I deem it necessary.
Problem solved, at least that one.

I was in manual mode as well and still saw APFS snapshotting happening. Which I think was causing a lot of my writes.

 

[Dockland]

Got this in my feed

How worried should you be about your M1 Mac’s SSD lifespan?

Users are concerned over SSD lifespan with the M1 swapping from memory under heavy loads. It's not something to ignore, but the fact is, SSDs last a lot longer than most people think.

www.macworld.com

 

[VitoBotta]

ok SO I tried something new, and so far it seems to have positive results. I added my entire drive as an exclusion to time machine, and in 18 hours kernel_task has only written 44GB total. Thats a dramatic decrease it would have been in the several hundreds by now. Curious for other folks to try it and see what happens.

interesting, I’m gonna try the same. My data is on an external drive anyway and in the worst case I can reinstall macOS from scratch.

 

[VitoBotta]

Got this in my feed

How worried should you be about your M1 Mac’s SSD lifespan?

Users are concerned over SSD lifespan with the M1 swapping from memory under heavy loads. It's not something to ignore, but the fact is, SSDs last a lot longer than most people think.

www.macworld.com

The article talks about 15 TB in two months. I’m at 155 in a bit over that period of time!

 

[telo123]

I've had my 8 GB MBA M1 since November and I only have 4 TB written and that's after installing multiple OS's (beta and subsequent removal and reinstallation of the public releases) and downloading approximately 652 GB worth of movies, games, TV shows, and other large files onto both an external hard drive and the internal. Time Machine is also being used on the daily. I do basic 4k editing with iMovie as well.

Guess I'm lucky and not as affected compared to others here!

Side Note:

I do use Chrome instead of Safari because the way that Safari caches things causes swap memory to be used (normal use with 1-2 GB), even with only 2-3 tabs open. Some of my school websites for eLearning that refuse to make their website more efficient with WebKit causes even higher SWAP (bordering around 4-5 GB) memory to be used. Chrome with 6-7 tabs that I frequently visit uses < 300 MB of swap memory to be used according to Activity Monitor (which is great for the SSD I guess)! I think the Silicon Version of Chrome is no longer resource-intensive compared to its Intel version. Same battery life for those who are wondering (I have the VP9 experimental flag on for hardware decoding on YouTube - prevents high CPU usage to render 4k video).

 

[TheSynchronizer]

I've had my 8 GB MBA M1 since November and I only have 4 TB written and that's after installing multiple OS's (beta and subsequent removal and reinstallation of the public releases) and downloading approximately 652 GB worth of movies, games, TV shows, and other large files onto both an external hard drive and the internal. Time Machine is also being used on the daily. I do basic 4k editing with iMovie as well.

Guess I'm lucky and not as affected compared to others here!

Side Note:

I do use Chrome instead of Safari because the way that Safari caches things causes swap memory to be used (normal use with 1-2 GB), even with only 2-3 tabs open. Some of my school websites for eLearning that refuse to make their website more efficient with WebKit causes even higher SWAP (bordering around 4-5 GB) memory to be used. Chrome with 6-7 tabs that I frequently visit uses < 300 MB of swap memory to be used according to Activity Monitor (which is great for the SSD I guess)! I think the Silicon Version of Chrome is no longer resource-intensive compared to its Intel version. Same battery life for those who are wondering (I have the VP9 experimental flag on for hardware decoding on YouTube - prevents high CPU usage to render 4k video).

I've made posts about this before, and I can second using Chrome/Edge instead of Safari to greatly reduce my writes on my M1 MBP.

But in my case I'm using the M1 Native Beta version of Microsoft Edge, with The Great Tab Suspender 7.1.6, and I've found browsing with this setup leads to writes substantially lower than when using Safari. The Safari caching seems to be a big factor in my SSD writes, but interestingly some others using Safari seem to not have an issue, but I guess they could just be browsing a lot less intensively.

Even though I definitely believe Safari is one of the culprits in this issue, I do believe that there are other factors at play too as some users are reporting much lower writes completely, no matter how they use and abuse their system.

 

[VitoBotta]

I am about to erase the disk and reinstall macOS, hoping that this helps somehow...