ssd swap - high usage of Terabytes Written

[Mike Boreham]

As you say it would be very interesting to know what "percentage used" values show for some of the really high users who have posted here.

What is your TBW that gives you the 1% number?

My usage numbers are 0% with 21.73 TBW to a 512GB internal new in November 2020.

@leons Just asking again about your TBW value and drive size that go with your 1% usage from Mac Analytics Data. Fine if you are unwilling to give it but re-asking in case it has gone under the radar.

So far all the reports here from Mac Analytics Data have been 0% usage except your 1%.

 

[Fomalhaut]

@leons Just asking again about your TBW value and drive size that go with your 1% usage from Mac Analytics Data. Fine if you are unwilling to give it but re-asking in case it has gone under the radar.

So far all the reports here from Mac Analytics Data have been 0% usage except your 1%.

I can provide a similar data point. My M1 Mini with 500GB SSD has just recently ticked over to 1% used, with 25.9TB written

My MBP16 with a 1TB SSD, and 178TB written shows 2% used.

The proportions don't quite agree, but they are in the ballpark. If my MBP16 were just about to tick-over to 3%, that would imply that 1% usage roughly equates to 60TB written, so maybe the M1 SSD with half the capacity would be at 1% after about 30TB. It's close to the actual figure, but I had hoped that I would be closer to 40TB written before seeing 1% used.

Just as well MacOS 11.4 was released when it was!

It would be interesting to see the "data written" number for other people reporting 1% used, together with their SSD size.

 

[Mike Boreham]

I can provide a similar data point. My M1 Mini with 500GB SSD has just recently ticked over to 1% used, with 25.9TB written

View attachment 1785010

My MBP16 with a 1TB SSD, and 178TB written shows 2% used.

The proportions don't quite agree, but they are in the ballpark. If my MBP16 were just about to tick-over to 3%, that would imply that 1% usage roughly equates to 60TB written, so maybe the M1 SSD with half the capacity would be at 1% after about 30TB. It's close to the actual figure, but I had hoped that I would be closer to 40TB written before seeing 1% used.

Just as well MacOS 11.4 was released when it was!

It would be interesting to see the "data written" number for other people reporting 1% used, together with their SSD size.

Thanks very much. That is indeed a good data point since it just changed to 1% at 25.9TB. Mine should be changing to 1% in a few weeks.

 

[TheSynchronizer]

I can provide a similar data point. My M1 Mini with 500GB SSD has just recently ticked over to 1% used, with 25.9TB written

View attachment 1785010

My MBP16 with a 1TB SSD, and 178TB written shows 2% used.

The proportions don't quite agree, but they are in the ballpark. If my MBP16 were just about to tick-over to 3%, that would imply that 1% usage roughly equates to 60TB written, so maybe the M1 SSD with half the capacity would be at 1% after about 30TB. It's close to the actual figure, but I had hoped that I would be closer to 40TB written before seeing 1% used.

Just as well MacOS 11.4 was released when it was!

It would be interesting to see the "data written" number for other people reporting 1% used, together with their SSD size.

This aligns with my 256GB SSD which is 2% at 25.2.

The 500GB is expected to essentially have twice the amount of lifespan and so this shows the percentage is pretty accurate across the board.

 

[leons]

@leons Just asking again about your TBW value and drive size that go with your 1% usage from Mac Analytics Data. Fine if you are unwilling to give it but re-asking in case it has gone under the radar.

So far all the reports here from Mac Analytics Data have been 0% usage except your 1%.

@Mike Boreham - Sorry, I missed your previous request. Although there does seem to be a small varaiability in the numbers, mine is roughly consistent. I was concerned about TBW at the time, so I was checking on a regular basis to see when it changed to 1%. I checked at 14.85 and it was still at 0%. The next day, it read 14.88 and was at 1%. So, it looks like it changed over to 1% slightly later than some of the other numbers would imply. Not sure why the variability, but still in the ballpark. For me, a non-issue anyway, since I am now seeing about 1TBW/month, so it will be more than a year before I cross over to 2%.

 

[souko]

For me on M1 MBA 8/256 15.3TBW and 1%. I do not know when it changed to 1%.

 

[Mike Boreham]

@Mike Boreham - Sorry, I missed your previous request. Although there does seem to be a small varaiability in the numbers, mine is roughly consistent. I was concerned about TBW at the time, so I was checking on a regular basis to see when it changed to 1%. I checked at 14.85 and it was still at 0%. The next day, it read 14.88 and was at 1%. So, it looks like it changed over to 1% slightly later than some of the other numbers would imply. Not sure why the variability, but still in the ballpark. For me, a non-issue anyway, since I am now seeing about 1TBW/month, so it will be more than a year before I cross over to 2%.

Thanks. I assume you have a 256GB M1, which makes it fit in with the other numbers emerging? :-

Mike Boreham 0% 21.7TB 512GB
Formalhaut 1% 25.9TB 512GB
The Synchroniser 2% 25.2TB 256GB
Souko 1% 15.3TB 256GB
Leons 1% 14.9TB 256GB

Recognising it is not very precise because we don't always know when it flipped to the next percentage and the percent values are only whole numbers.

I am pretty much ready to switch off the issue having established that I am likely to use 1% per 7 months.

 

[k-hawinkler]

Thanks. I assume you have a 256GB M1, which makes it fit in with the other numbers emerging? :-

Mike Boreham 0% 21.7TB 512GB
Formalhaut 1% 25.9TB 512GB
The Synchroniser 2% 25.2TB 256GB
Souko 1% 15.3TB 256GB
Leons 1% 14.9TB 256GB

Recognising it is not very precise because we don't always know when it flipped to the next percentage and the percent values are only whole numbers.

I am pretty much ready to switch off the issue having established that I am likely to use 1% per 7 months.

1% in 7 months, that’s 100% in 58 years.

 

[k-hawinkler]

Rule of thumb:

Apple M1 SSDs are good for about 5,000 TBW for each 1 TB of capacity.

Or in other words about 5,000 writes per SSD storage cell.

Cheers, K-H.

 

[leons]

As a funny aside, although these are SSDS (Solid State DRIVES), which evokes visions like this:

In actuallity, we've all spent trhe last 110 pages discussing a chip that measures about 2x1x.1 inches!

 

[adcx64]

I have had my M1 MacBook Pro since February, and I use it daily (8GB) with many apps open, Parallels and Crossover, and I'm only at 2.4tb TBW.

You people need something else to worry about.

 

[thadoggfather]

I have had my M1 MacBook Pro since February, and I use it daily (8GB) with many apps open, Parallels and Crossover, and I'm only at 2.4tb TBW.

You people need something else to worry about.

but clearly from the results yours aren’t everyone’s

mine has been good too since late December and even better with 11.4, non issue, but I won’t scoff at people that are writing like 30tb in a day. That ain’t “write”

 

[TheSynchronizer]

I have had my M1 MacBook Pro since February, and I use it daily (8GB) with many apps open, Parallels and Crossover, and I'm only at 2.4tb TBW.

You people need something else to worry about.

Your situation is different.

I’ve owned my M1 since launch day when Big Sur was a lot more buggy, and the issue described here was real and problematic and potentially tragic due to soldered SSD, hence why there’s 110 pages in this thread.

But fortunately it’s pretty much been fixed as of today, so nothing to worry about anymore!

 

[Kung gu]

We got confirmation that it was a XNU/kernel bug.

 

[wirtandi]

Out of curiosity, what is this XNU bug?

 

[Fomalhaut]

I have had my M1 MacBook Pro since February, and I use it daily (8GB) with many apps open, Parallels and Crossover, and I'm only at 2.4tb TBW.

You people need something else to worry about.

Ever heard the expression "your mileage may vary"?

 

[dsusanj]

For me on M1 MBA 8/256 15.3TBW and 1%. I do not know when it changed to 1%.

As my M1 MBP 8/256 has just switched to 1% in the past couple of days I can confirm this has happened somewhere between 14.5 and 16.5 TBW.

 

[Icelus]

Out of curiosity, what is this XNU bug?

XNU is the name of macOS's kernel. So this was a kernel bug.

XNU - Wikipedia

en.wikipedia.org

 

[Maximara]

@Mike Boreham - Sorry, I missed your previous request. Although there does seem to be a small varaiability in the numbers, mine is roughly consistent. I was concerned about TBW at the time, so I was checking on a regular basis to see when it changed to 1%. I checked at 14.85 and it was still at 0%. The next day, it read 14.88 and was at 1%. So, it looks like it changed over to 1% slightly later than some of the other numbers would imply. Not sure why the variability, but still in the ballpark. For me, a non-issue anyway, since I am now seeing about 1TBW/month, so it will be more than a year before I cross over to 2%.

Just to clarify. The way the perchange works is it rounds to the closest integer. So 0.4999... rounds to 0% but 0.500...1 rounds to 1% So the quick and dirty formulas are:
14.85 x 100 / 0.4999 or ~2970 TBW for 100%
14.88 x 100 / 0.5 or ~2976 TBW for 100%

So 2900 TBW for 100% seems within reason.

 

[xxBlack]

Last week just 120 mb swap on my 8 GB RAM instead of 1,5-2 GB

 

[Chompineer]

As a funny aside, although these are SSDS (Solid State DRIVES), which evokes visions like this:
View attachment 1785211

In actuallity, we've all spent trhe last 110 pages discussing a chip that measures about 2x1x.1 inches!

What exactly do you think is inside that 2.5" housing? It's a tiny board with said tiny chips and a controller, and a ton of void space. They come in 2.5" as that is a standardized form factor for spinning laptop drives.

The only difference is the NAND chips and controller are soldered to the board and do not need to come in a standardized form factor.

 

[jordysak]

Sorry if this is already discussed; my main concern is Microsoft Teams .. I use it daily for video calls with colleagues for 2 hours each day and this is perhaps the only intel app I use. My other usage has to do with Logic Pro , Final Cut Pro etc but they are all M1 optimised apps..

So is Microsoft teams something to be worried about?
MacBook Pro M1 16GB 256GB (MacOS 11.3.2).

how do I check the SSD usage?

 

[Icelus]

Sorry if this is already discussed; my main concern is Microsoft Teams .. I use it daily for video calls with colleagues for 2 hours each day and this is perhaps the only intel app I use.

Did you try the web client with, for example, Safari?

 

[jordysak]

Did you try the web client with, for example, Safari?

You mean using Microsoft Teams via the web? I didn’t try that, if the SSD is in fact impacted by it then sure I’ll find al alternative but how can I check if indeed it does have a higher consumption on my SSD

 

[rob984]

Sorry if this is already discussed; my main concern is Microsoft Teams .. I use it daily for video calls with colleagues for 2 hours each day and this is perhaps the only intel app I use. My other usage has to do with Logic Pro , Final Cut Pro etc but they are all M1 optimised apps..

So is Microsoft teams something to be worried about?
MacBook Pro M1 16GB 256GB (MacOS 11.3.2).

how do I check the SSD usage?

No, I was on few teams meetings in last few weeks and they were 7-10 hours long, did not notice much of disk writes. I think on those days I got around 5GB writes, 10 tops on those days, and it was on BS 11.3.1, now it might be even better.