I’ve gotten a number of emails asking me about SSD swap issues with the new M1 Macs made by Apple and if they as new owners of M1 Macs should be concerned. Thus I decided to write this article explaining the issue, and giving you as much factual information to help you to decide if you should be concerned or not. First some background.
Every computer has two things. RAM which stands for Random Access Memory and storage which in the M1 Mac’s case is an SSD or Solid State Drive. Your programs run in RAM. But when that starts to fill up because you have a lot of apps open, or when macOS decides it’s not optimal to have so much data in RAM, it will do a swap of the data to the SSD to free up RAM. This will move some data from the RAM to the SSD which frees up RAM. And when it’s required, it will swap that data back. Every operating system does this. By that I mean Windows and Linux among others.
Now this is great, but a Twitter user named Longhorn posted this Tweet about his two month old M1 Mac:
Now SSDs have a lifespan that is calculated on the amount of writes that it does. Data recovery company Ontrack estimates this to be 60 to 150 terabytes written. So based on the Tweet above, going through 1% of the drive’s life in two months is insane as it will wear out the SSD faster. And the fact that you cannot replace the SSD once it fails doesn’t help.
Once that Tweet started to go viral, other users of M1 Macs reported the same thing. So clearly there’s an issue here. But if you own an M1 Mac, should you be concerned?
Well, for starters, I would say it’s a issue for all Mac owners as during the process to research this story, the same phenomena is happening to Intel based Mac owners as well:
That implies to me that this is more of an issue with macOS than an issue with the M1 chip. That also got me curious to see what my SSD stats are on my 15″ MacBook Pro from 2015. So I used a paid utility called DriveDx to find out:
So at least my drive isn’t going to die anytime soon. And it implies that I do not have this problem. So what is the issue? I have a few guesses:
- During my research, some users found that some applications are causing this excessive wear. This Reddit thread for example points to Lightroom as being a cause of this issue. So in theory, any memory intensive app could cause this issue to happen.
- macOS being way too aggressive about swapping to disk in certain circumstances. Rosetta 2 emulation for M1 Macs for example has been fingered as a culprit.
- A bug in tools that report on drive health mis-reporting the drive health.
The fact is that we don’t know. But given how popular Macs appear to be these days, especially the M1 processor based Macs, I think we need to find out. Now it’s a safe bet that Apple is looking at this. And they might be working on a fix or already have a fix. It would be nice if they said something though as they are giving users the silent treatment as usual.
Now if you are worried about this issue, I have some suggestions:
- If you are buying a new M1 Mac, buy a 16GB model or more. That is likely to swap to disk less.
- Higher SSD storage options tend to have longer lifespans in terms of the amount of writes that it can do. So you can buy a 512GB or 1TB or higher M1 Mac to mitigate this issue.
One thing that I would not do is disable the ability for macOS to swap to disk. Swapping to disk is there for a reason and you will likely take a performance hit if you disable it.
The bottom line is that I don’t think that this is an issue that you need to worry about. At least not with the evidence that exists at present. But if you are worried about this issue, there are some mitigations that you can take. But it would be nice if Apple speaks to this and addresses this in a timely manner. That would make all mac users feel better.