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ssd swap - high usage of Terabytes Written
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I doubt the stats are off. That's what is reported by the smart of the disk. I also have the 16". And my one also had like a TB or so of usage right after setting it up.
It could be that they wrote the full disk once for testing purpose. Which is a round 3.84TiB for a 4TB disk.
It could be that they wrote the full disk once for testing purpose. Which is a round 3.84TiB for a 4TB disk.
Yeah it was. Apparently my Mac decided to download the 11.4 update while I was working.
maybe i'm missing something? but if this is "fresh out of the box" isn't the power cycle count at 231 a concern? and what about the 35 unsafe shutdowns?
Thank you!
I remember when the M1 Macs first came out a lot of reviewers talked about how 8GB seems to be much more than on Intel Macs. Do you think it was just because this bug wasn’t reporting memory pressure correctly?
My 8GB M1 is still working just as magically as it’s always been but as of 11.4 I’m definitely experiencing the lowest writes so far, although I haven’t had an issue with SSD writes for quite some time now so it’s not a big difference. Memory pressure is definitely higher now but it hasn’t affected performance at all as far as I can tell, and for my purposes it still functions just as well if not better than my old 16GB intel macbook did (which my 8GB intel macbook before that one didn’t)
8GB on M1 does not equal 16GB on an intel mac. For some workflows, more memory is more memory i.e. for 8K video editing a 16GB intel would probably perform better. But at the same time 8GB on M1 also functions differently (and better) compared to 8GB on intel macs.
No, that’s unrelated. The notion that less RAM on M1 somehow equals more RAM on Intel is of course wrong, after all, RAM is RAM, but it is indeed a fact that M1 usually remains quite responsive under high memory pressure scenarios where Intel machines would grind to a halt.
No definitive explanation for this has been given, but it has been speculated that larger memory pages, built-in SSD controller and an optimized virtual memory subsystem allow macOS on M1 to juggle RAM around much quicker than an Intel system could.
Internaut
macrumors 65816
Another 14.4 observation: The swap used figure remains low. Likewise for the bytes written by all the processes, since last reboot, but the memory pressure graph is far more likely to show prolonged periods of yellow rather than the usual green. I don't know how to interpret this graph and what I googled gave no real guidance. I see no performance problem when the graph is yellow.
This could have implications for what we can achieve (or at least effectively be running and multi tasking) at any given time, with a base level M1 Mac, unless there is some sort of pressure valve in macOS's plumbing to allow for more swap space and bytes written when needed.
This could have implications for what we can achieve (or at least effectively be running and multi tasking) at any given time, with a base level M1 Mac, unless there is some sort of pressure valve in macOS's plumbing to allow for more swap space and bytes written when needed.
The power cycles refer to the SSD, not the computer. The SSD will sleep many times during the up time of the computer, during periods when disk access is not required.
The 11.4 update makes use of 90% of the available RAM and then if need be uses swap. This is the correct approach.
Before 11.4, macOS would use swap immediately without even filling up most of the available RAM.
The person who discovered this issue says it could have been a bug in the macOS kernel which was fixed in 11.4.
Internaut
macrumors 65816
That would seem consistent with what I'm seeing. I needed to load a couple of Intel apps, earlier (Trello and Teams, in their application form rather than web), on top of everything else and the swap space did go up from just under 100MB to just south of 700MB. Prior to 11.4 this would have been in the 2-3GB range with a lot of writing.
So, rather happy with the upgrade!
So today I installed 11.4 and my attention was drawn to the ssd usage again. This is my output. It seems a bit excessive.... Is this a reason to return the computer?
Just to add, this is an M1 air from the end of November.
Just to add, this is an M1 air from the end of November.
Code:
=== START OF SMART DATA SECTION ===
SMART overall-health self-assessment test result: PASSED
SMART/Health Information (NVMe Log 0x02)
Critical Warning: 0x00
Temperature: 42 Celsius
Available Spare: 100%
Available Spare Threshold: 99%
Percentage Used: 14%
Data Units Read: 483,547,790 [247 TB]
Data Units Written: 427,002,850 [218 TB]
Host Read Commands: 1,840,183,469
Host Write Commands: 1,238,214,075
Controller Busy Time: 0
Power Cycles: 299
Power On Hours: 901
Unsafe Shutdowns: 58
Media and Data Integrity Errors: 0
Error Information Log Entries: 0This looks a bit excessive. Unless you're rendering 8K video the whole day or do some other write intensive workloads.
It's about 240GiB per hour on average.
It's about 240GiB per hour on average.
I did some work in Xcode during two or three months and was running out of resources quite often. I would have to restart Xcode because of too many open files, unable to run the simulator. Fortunately that restart happens quickly.
Then there's excessive swapping.
The other day I had a lot of windows with tabs open in Safari and my disk space evaporated from 15Gb free to 1,5Gb free, then the system crashed. I've stopped using Safari next to Firefox and/or Brave because this eats my resources like nothing else. I have 8Gb RAM and a 256 ssd. Frankly I cannot wait until a M2 pro with a larger screen and more resources comes out which will force me to break the piggy bank again.
Internaut
macrumors 65816
I'm surprised it ran it all with 1.5Gb free. On my 2015 MacBook Pro, Photoshop would throw a fit if I went below 12Gb. macOS and some of the main applications just seem to like plenty of floor room to play with. I thought 256Gb would be great, moving from a 128Gb base model, but now I'm not so sure (couple of virtual machines and it is on the edge of 100Gb).
One day of usage? That data is meaningless to check for excessive disk writes, it could be a disk that was tested during initial loading for a while in the factory. I would rather install DriveDX or smartctl and check the delta in writes after a week or 10 days of normal usage, then decide.
Install 11.4 before doing the before-after math.
Apparently SSD writes are fine for everybody now (finally!).
If you mean that 4TB are too much for a new machine I would not care at all. For your SSD that's nothing, as your stats clearly declare: percentage used 0%. Your SSD will probably survive the rest of the machine and probably many of the readers of this post. (Which I don't know whether it is reason for joy or sadness)
Welcome to the ‘stopped using Safari’ club
.If I kept using Safari to this day ever since I noticed heavy SSD writes some time in December, I’d probably be on atleast 400TB written and counting. But I was lucky enough to notice the issue quite early and I switched from Safari to any other browser, and it’s honestly the biggest reason why my SSD wrote 23.1TB between November 26th and December 30th, and now since then it’s only written 2TB in 6 months and as of now I’m on 25.1 TB.
I think if you take any steps needed to circumvent the issue on your part now, you’d still have a macbook that would last for a very long time. E.g. if you were to write ~4TB a year like I do now, or even something larger like 20TB a year, then your mac would likely still last for more than 24 years, and maybe even 50+ years (these SSDs seem to be rated at around 1400TBW according to the percentage used value).
Currently I use Firefox with a few tweaks and modifications, which I’ve even managed to make look like Safari - I browse with 100s+ of tabs all the time with no issues as a computer science student.
I highly recommend it, and if you want I can point you to useful tweaks and modifications that reduce swap writes even further. Other good browser choices that I know of are Brave, Edge and Vivaldi.
It’s not too late!
Are you serious? 1.5 GB free? You must leave about 10% of the total storage free for the temporary system files, in your case at least 25 GB. One reason to the excessive amount of the written data can be exactly the lack of free space because then the system has to swap files all the time to free new space for new temporary files. Why don't you use an external disc for you work?
I am trying to leave at least 15 to 20 Gb of space by putting as much as I can on my NAS. Currently I have 21 Gb free after another round of cleanup with disk Inventory X.
But have you ever installed Xcode?
I would say 5GB/hour is quite healthy - let's say 50GB/day if you are working for 10 hours per day, or 1-1.5TB per month. You would comfortably exceed the likely usable life of the machine. I personally want my gear to last at least 10 years, even if I had gifted or sold it before that time.
Some people have reported over 1TB of writes per day, so around 100GB/hour for a full working day.