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ssd swap - high usage of Terabytes Written
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Wait, 1.6TB since Feb, with daily usage? This number is really, really good lol
I've had 5 TBW in about a week of owning base model m1 macbook air, which to me is clearly unacceptable.
It's not even my primary computer, and I wasn't doing anything particularly write intensive, sometimes kernel_task would just keep writing and writing for no discernible reason so I would reboot to "fix" it for a time being.
Did some of the things mentioned in OP, no help except maybe switching to edge browser; last night left computer running with only edge and multiple tabs and it only wrote 10 GB. I'm considering reformatting, not installing anything then 1 by 1 to see if it's a particular program that is triggering this sort of runaway kernel task condition.
It's not even my primary computer, and I wasn't doing anything particularly write intensive, sometimes kernel_task would just keep writing and writing for no discernible reason so I would reboot to "fix" it for a time being.
Did some of the things mentioned in OP, no help except maybe switching to edge browser; last night left computer running with only edge and multiple tabs and it only wrote 10 GB. I'm considering reformatting, not installing anything then 1 by 1 to see if it's a particular program that is triggering this sort of runaway kernel task condition.
4 Months. M1 MacBook Pro 8G/256G for daily programming basics. MacOS 11.3.1
It was said that if "Percentage Used" is under 80%, the SSD speed will have worse performance eternally.
Code:
=== START OF SMART DATA SECTION ===
SMART overall-health self-assessment test result: PASSED
SMART/Health Information (NVMe Log 0x02)
Critical Warning: 0x00
Temperature: 33 Celsius
Available Spare: 100%
Available Spare Threshold: 99%
Percentage Used: 2%
Data Units Read: 76,566,448 [39.2 TB]
Data Units Written: 68,181,156 [34.9 TB]
Host Read Commands: 502,409,281
Host Write Commands: 309,964,574
Controller Busy Time: 0
Power Cycles: 193
Power On Hours: 333
Unsafe Shutdowns: 41
Media and Data Integrity Errors: 0
Error Information Log Entries: 0
I'm not sure what you mean. 2% Percentage Used means that SMART estimates that 2% of your SSD's life has been used, therefore you have 98% of SSD life left.
This is only an estimated value set by the manufacturer however and SSD's often go over 100%.
AFAIK performance of an SSD only starts getting noticeably slower when you fill the storage space up >90% of its total capacity. Where did you read that the percentage used value would have an effect on the speed of the SSD?
Yes. 16GB model, I rarely if ever see any swap in use.
My MacBook is mostly for casual browsing and as a side computer (PDF's/Documents and such accompanying my desktop). Biggest memory impactor I have is some very large PDF's.
They are correctly calculated estimates. Not sure why that is hard for you to understand. Seems pretty simple.TIL it's possible for something to be both correct and an approximation.
34.9 TBW in only 4 months? A this rhythm your machine will be completely ****ed in one year and half.
Percentage used I don't think is about lifespan but to data unavailable on data available.
There is no way that a 256 GB SSD with already 34.9 TBW is at 2% of lifespan.
Why not? If the TBW is 1600 TB then it fits fine. And has been pointed out many times on this thread, the percentage used doesn't have to be linear for all writes to the drive. It is an estimate that Apple makes based on what is likely to be a variety of undisclosed parameters.
Right. The quick and dirty TBx100/percentage (based on the 2014 test) results in 1745 TBW which given the range makes a 1600 TBW totally reasonable. More over if 4 months = 2% then based on the test 100% = 200 (4 x 50) months or 16.7 years. Even if we cut that in half it is still 8.3 years.
As I said before people look at only part of the data and freak out when the other parts indicate something totally different.
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I’ve had a chance to test this for myself now. RAM is used up almost instantly when importing photos and editing in Lightroom. Disk writes etc not bad though and the swap size wasn’t terrible.
Got mine in February , 16 GB / 256 SSD . Same numbers
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It looks like it is resolved by 11.4 RC for me on M1 MBA 8GB.
Hi souko, that's great to hear, do you mind sharing more details? For example, is it resolved for all apps, etc.
My M1 16GB/1T MBA should arrive next week, I only ordered after reading all this thread. In fact, I ordered that version as a precautionary (or rather paranoid) measure.
Thanks!
Hi, it is resolved for all apps. (Safari, Chrome, Edge, Mail, Calendar, Notes, Reminders, Photos, Affinity Photo, Pixelmator Pro, Apple tv, Podcasts, Apple Music, Messages, Signal, Telegram, NordVPN, Coconut battery, Airbuddy 2, probably more. These I tried.)
I had about 400GB written per day. I can not say how much it is exactly after 11.4 - too short time. (I went from 11.3.1 public to 11.4 RC) But it looks like it will be under 50GB/day even with heavy use. (30 tabs open, 10 other apps open - Mail, Messages, Signal, Telegram, NordVPN, Podcasts, Apple Music, Apple tv, Monitor activity, Coconut battery.) I will update this post after few days for exact numbers. One change is that in Activity monitor I see memory pressure in orange. (I know I should have gone for 16GB memory, I will go for it after MBP14" release.)
I do not do anything to lower ssd swap, just use the machine.
Some other questions?
Hi guys! I'm waiting to receive my brand-new MBA M1 16gb/512gb 8C/7C later this week. I would like to monitorize memory swap whilst I still am on time to return the computer. I saw the tutorial in the first post, dou you suggest any way simpler? Thanks
Thanks a lot for the detailed answer.
This will be my first Mac computer and tha info is very comforting to hear. I just hope 11.4 is ready in my first power up.
Have a great day!
It looks like 60GB/day (but I was not using MBA much today, so maybe average will be slightly more). Important note: I see kernel_task (culprit of excessive write for me) writing only when is unified memory full and system is using swap to ssd. If there is 2GB swap, system (kernel_task) writes only 2GB.
I use MBA as my main computer 4-12h/day.
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I Installed 11.4 RC and so far things look good. I decided to open up 22 apps over 2 desktops at the same time to see how the Mini coped and I was impressed. Everything ran nicely and the memory optimisation hadn’t instantly started to use swap. Photoshop, Lightroom CC and Lightroom Classic all open. Data written over a 4 hour period only 6gb.
