ssd swap - high usage of Terabytes Written

[Kung gu]

So performance will be worse or better on 8GB? I’m kind of confused with your comment on higher memory pressure.

sorry, I should have more clearer.

Performance will be the same, the M1 did not get slower but now swapping occurs less.

You see before 11.4 kernel_task was writing so much to the disk for no reason. Apple fixed that and also fixed the usage of excessive swap.

RAM usage on 11.4 will we like the intel models(i.e disk writes will be lower and swap will be normal and not crazy high). Don't worry the M1 performance is not impacted. The system will still feel snappy and quick.

As for memory pressure, well for normal tasks(web browsing, zoom, emails) 8GB is fine but heavy tasks like video editing or having a lot of apps open its best to opt for 16GB.

TLDR: 11.4 has better disk and RAM management. M1 performance is the same.

 

[mi7chy]

So performance will be worse or better on 8GB? I’m kind of confused with your comment on higher memory pressure.

Sounds like explanation is implying that with 11.4 it's swapping to storage less to reduce excessive SSD writes while using more RAM so worse for those with 8GB. Maybe write Tim Cook to see if you can exchange and pay the difference for 16GB model since the fix for the OS bug made the 8GB model worse.

 

[CMMChris]

Performance will be the same, the M1 did not get slower but now swapping occurs less.

Unlikely. Moving from swap to available RAM increases performance due to the higher bandwidth of the RAM. That is underlined by the fact that a lot of people say that 11.4 feels significantly smoother compared to 11.3. And I actually have that feeling as well.

Sounds like explanation is implying that with 11.4 it's swapping to storage less to reduce excessive SSD writes while using more RAM so worse for those with 8GB.

For those with the swapping issue there has never been an issue with a lack of RAM. RAM pressure mostly was green despite the heavy writes to the SSD / excessive swapping. The machine now using the available RAM instead of the swap is beneficial.

 

[mi7chy]

So, can anyone confirm that 11.4 finally fixes the SSD issue for sure?

Too soon to tell. Give it at least a week which is about how long it'll take for me to retest extended sleep that I saw used up all 16GB RAM then created a swap file with only one browser tab opened.

 

[Chancha]

As a 8GB Air owner I would be bumped if this fix means less performance for my use cases. Something has to give, if the previous state of M1/Big Sur was to sacrifice SSD tear in exchange for performance in swap, this fix could mean the bottlenecking is being put back to physical RAM amount. Fingers crossed.

 

[featherlessbird]

The SSD writes are much lower on 11.4, but the issue isn't completely fixed for me. I'm still seeing about 1TB of kernel_task writes a day if I don't reboot my Mac for a couple of days. The same on 11.5 beta. No difference in performance though.

 

[tollickd]

I do hope 11.4 has resolved the main culprit of the issue. Noting more frustrating than seeing the Memory Pressure 50% or less sometimes and the OS dumps straight to the swap! I have ram use it OS!!!!

 

[Kung gu]

The SSD writes are much lower on 11.4, but the issue isn't completely fixed for me. I'm still seeing about 1TB of kernel_task writes a day if I don't reboot my Mac for a couple of days. The same on 11.5 beta. No difference in performance though.

What were your SSD writes prior to 11.4?

1TB kernel_task writes is definitely not normal. Maybe do a fresh install of macOS.

 

[featherlessbird]

What were your SSD writes prior to 11.4?

1TB kernel_task writes is definitely not normal. Maybe do a fresh install of macOS.

Over 3TB a day. I've tried reinstalling the OS a couple of times but it didn't help.

 

[IceStormNG]

Are you sure it's caused by swapping? kernel_task does a lot more than just swapping.

You could try to temporarily disable swap completely and look whether it changes your writes. If not, then your issue is not caused by swapping but something else.

3TB and even 1TB a day seems excessive. Assuming 8h per day, it would be about 2GB per minute or 125GB per hour (at 1TB per day).

 

[Kung gu]

Over 3TB a day. I've tried reinstalling the OS a couple of times but it didn't help.

oh my. So 11.4 removed 2TB writes per day. Nice.

If you don't mind me asking what apps do you run your Mac?

Is it heavy workloads then I would say 11.4 has done its job in reducing your writes.

If it's not heavy like simple web browsing then something is wrong with your Mac.

 

[featherlessbird]

If you don't mind me asking what apps do you run your Mac?

Chrome with dozens of tabs, Edge, VS Code, Discord, Spotify, some other Electron-based apps. Chrome is most likely the main contributor, although not the only one.

 

[Mc0]

Chrome with dozens of tabs, Edge, VS Code, Discord, Spotify, some other Electron-based apps. Chrome is most likely the main contributor, although not the only one.

Do you happen to use Spotify Web player? because I've been using the web player and I notice that my writes is higher when I use Spotify compare to when I just play random songs on YouTube. My average writes when I use Spotify web player is 70GB per day vs the 40-50GB per day when I DON'T use it. I'm a full stack developer and I don't perform resource intensive tasks.

 

[featherlessbird]

Do you happen to use Spotify Web player? because I've been using the web player and I notice that my writes is higher when I use Spotify compare to when I just play random songs on YouTube. My average writes when I use Spotify web player is 70GB per day vs the 40-50GB per day when I DON'T use it. I'm a full stack developer and I don't perform resource intensive tasks.

I've tried the web player for some time, but didn't notice much of a difference in writes compared to the regular app, so I switched back.

 

[Internaut]

I've not taken a hard look at the write figures for a while, but the swap used figure on my base MacBook Air looks better since I did the OS upgrade this morning (Edge running with a few tabs, Word, Excel, Podcasts, Twitter all running).

 

[Maximara]

What were your SSD writes prior to 11.4?

1TB kernel_task writes is definitely not normal. Maybe do a fresh install of macOS.

Over 3TB a day. I've tried reinstalling the OS a couple of times but it didn't help.

You do know all this reinstalling is "using up" the TBW of the SSD, right?

 

[featherlessbird]

You do know all this reinstalling is "using up" the TBW of the SSD, right?

Well, I think it's negligible compared to the overall TBW of 280TB in four months.

 

[sneeks]

The process that runs most often now on my Mac is photolibraryd, i may disable photos from syncing with my Mac as i don't really need them on it. Some light use tonight watching YouTube in Firefox and then it was left in sleep mode for 3 hours. All appears ok to me.

 

[KDPlazed]

Can someone explain to me about why com.apple.StreamingUnzipService is writing a lot of data? I just bought the air a few days ago. Is it normal for this to happen?

 

[Kung gu]

Can someone explain to me about why com.apple.StreamingUnzipService is writing a lot of data? I just bought the air a few days ago. Is it normal for this to happen?

Make sure to update to 11.4.
Monitor it for a week. It should be fine, it's not a lot.

 

[bojan233]

11.4 has helped me, so far so good.

Was doing about 100gb per day on base model air with powernap=0 and using firefox with tab discard, now getting about 20gb, relatively casual use.

Completely fine with this, and very happy... performance not affected at all.

 

[mr_jomo]

Can someone explain to me about why com.apple.StreamingUnzipService is writing a lot of data? I just bought the air a few days ago. Is it normal for this to happen?

OK guess - but (based on size and timing) that could probably be the macOS 11.4 update being streamed and unpackaged or based on the appearance of com.apple.mobilesoftwareupdate ditto for an IOS or iPadOS update?

 

[bk42327]

If I look at my new MacBook 16 I received today I get
SMART/Health Information (NVMe Log 0x02)
Critical Warning: 0x00
Temperature: 35 Celsius
Available Spare: 100%
Available Spare Threshold: 99%
Percentage Used: 0%
Data Units Read: 4,129,182 [2.11 TB]
Data Units Written: 7,706,177 [3.94 TB]
Host Read Commands: 32,807,784
Host Write Commands: 28,353,991
Controller Busy Time: 0
Power Cycles: 231
Power On Hours: 13
Unsafe Shutdowns: 35
Media and Data Integrity Errors: 0
Error Information Log Entries: 0


The SSD according to smartctl has been up for 13 hrs now and has a total write of nearly 4 TB, that makes - in the 12 hr lifetime - 300+ GBps per hour.

Impossible to achieve, roughly a write rate of 44 Gbps? Or am I wrong?

 

[IceStormNG]

If I look at my new MacBook 16 I received today I get
SMART/Health Information (NVMe Log 0x02)
Critical Warning: 0x00
Temperature: 35 Celsius
Available Spare: 100%
Available Spare Threshold: 99%
Percentage Used: 0%
Data Units Read: 4,129,182 [2.11 TB]
Data Units Written: 7,706,177 [3.94 TB]
Host Read Commands: 32,807,784
Host Write Commands: 28,353,991
Controller Busy Time: 0
Power Cycles: 231
Power On Hours: 13
Unsafe Shutdowns: 35
Media and Data Integrity Errors: 0
Error Information Log Entries: 0


The SSD according to smartctl has been up for 13 hrs now and has a total write of nearly 4 TB, that makes - in the 12 hr lifetime - 300+ GBps per hour.

Impossible to achieve, roughly a write rate of 44 Gbps? Or am I wrong?

If I'm not completely wrong now:

3940GiB / 13h = 303GiB/h = 65GiB/m = 1.09GiB/s

Those SSDs write at around 2GiB/s. Totally possible. But that would mean, your Mac is hammering the SSD non-stop.

 

[bk42327]

If I'm not completely wrong now:

3940GiB / 13h = 303GiB/h = 65GiB/m = 1.09GiB/s

Those SSDs write at around 2GiB/s. Totally possible. But that would mean, your Mac is hammering the SSD non-stop.