Back in November, I predicted a potential issue with the new M1 Macs with regards to
swap memory and SSD degradation.
In the last 24 hours I’ve been alerted by several of my subscribers that this issue
may actually be legitimate and that there are some reports of it occurring.
Some people have reported their internal SSD has lost up to 10% of it’s total capacity
already with less than 2 months of usage.
Extrapolating on these results, if this information is accurate their SSD could likely fail within
2 years.
Now this video isn’t meant to scare you or be considered fear mongering, I’m simply
reporting on this topic as it’s developing and giving my own opinion on if it’s legitimate
and what could be causing it.
Now before we get into the video, if you’re not sure what role RAM, or random access memory
and also swap memory play, make sure to watch my previous video on the topic.
Now that you’re up to speed, let’s get into the most recent developments on this
topic.
There have been some M1 Mac owners claim that they’ve already seen massive amounts of
data both read and written to their internal SSD, and this is slowly killing their SSDs.
In this video I want to cover these claims and also try to look at some possible explanations.
There’s a big twitter thread going right now with various people posting their results.
One user reported over 150 terabytes of data units both read and written to his SSD, and
this was on a M1 MacBook Pro with 2TB SSD and 16GB of RAM, after only 2 months of usage.
It shows that his SSD has already degraded by 3%, or 60GB of total storage capacity lost
in just 2 months.
Worst case scenario, if these results are true he could lose a large part of his total
storage capacity or even face complete drive failure within 2 years.
Another user reported 280TB of written data units consuming around 10% of his total drive
capacity, less than 60 days in.
Now, granted, these are extreme cases and represent only a small fraction of users,
but there are some troubling posts on the twitter thread from users with similar, although
much less worse results.
Some have reported greater than normal SSD usage in the few months they’ve owned their
devices.
My own device recorded 45 terabytes of data units read and written to the internal SSD,
supposedly totalling about 1% degradation of the SSD.
This is since I bought my M1 MacBook Air base model in mid November, with relatively normal
usage.
It seems the main culprit is swap memory.
Contrary to popular belief swap memory is not a bad thing, and even sustained usage
shouldn’t have too much of an effect on the lifetime of your hard drive or SSD.
It’s been a normal thing in macOS and pretty much every other operating system for many
years, but the problem now it seems is that swap memory usage (caused either by the design
of the M1 or simply the macOS Big Sur operating system) is through the roof, and is having
a much bigger affect than it should.
Take a look at the bytes written value for the kernel_task process in my activity monitor.
This accounts for the total amount of swap memory used among other things.
I last restarted my M1 MacBook Air about 2 days ago, and it’s already written over
450GB of data.
This is with very light usage with about 10 tabs open in Firefox and nothing else.
Now, this amount of elevated swap usage and data units being written to the SSD compared
to normal expectations seems odd, but there may be a few things that can explain it.
Firstly, there’s no guarantee that the data we’re seeing is actually accurate.
The SMART reporting tools being used to measure SSD usage are third party tools, and not supported
or endorsed by Apple.
There’s a good chance that they are reading the data incorrectly or are just straight
up inaccurate.
Most people are using Homebrew to find this information, but there are other tools.
I’m using the free version of DriveDx which gives the same information.
Since this is so early in both the M1 lifecycle and the first instances of this issue, there’s
no way to tell how accurate these claims are just yet.
Secondly, it may just be that the Big Sur version of macOS is extremely eager to use
swap memory once you have more than a few apps open at the same time.
I have certainly noticed all of my M1 Macs using swap memory more than my Intel Macs.
If this is the case, and it is a software issue with macOS, the good news is that Apple
can easily fix this with a simple software update.
The third explanation is that this level of swap usage and increased amount of total data
units already written to the internal SSD is normal behaviour.
Apple may have designed the entire M1 architecture this way, and are relying on the supposedly
above average write ratings of their internal SSDs.
What this means is that the tools I mentionede previously are reporting correctly, but they
are mis-judging the amount of usage required to actually degrade the SSD.
This seems a little suspect to me because there’s nothing special about Apple’s
SSDs.
The potential lifespan of a drive can be referred to as Terabytes Written (TBW), referring to
how much data can be written to a drive that is covered by the manufacturer before there's
a chance it becomes unusable.
Apple apparently uses Toshiba TLC NAND SSDs.
Typically, the cells in an SSD are durable for around 3,000 read and write cycles, but
this can vary a lot depending on the quality of the drive.
We don’t know exactly what type of SSDs are inside the M1 Macs, but they certainly
aren’t some kind of super special high-tech proprietary Apple SSDs, so it can be safely
assumed that the TBW rating is going to be inline or perhaps at best slightly better
than most other high-end SSDs.
So what should you do if you have an M1 Mac?
Well, there’s no need to panic.
This is more than likely going to be some kind of minor issue that’s simply been blown
up by sensationalist news articles on the internet.
You can however look at your own total read and write data and add this to the ongoing
twitter thread.
You can use Homebrew or download a tool like DriveDx to show this.
Apple is certainly monitoring this situation and if enough people comment and provide data
and it does turn out to be an actual issue, I’m confident Apple will take steps to address
it.
I’ll more than likely make an update video on this topic in the near future, so stay
tuned.
Apart from that, thank you for watching this video, and if you have any comments or questions
please leave them down below, and I’ll catch you in the next one.