As wonderful as my M1 Mac mini is, it isn’t without its problems.

For instance, there’s the much publicised Bluetooth issues (which are largely fixed following macOS 11.2), and the distinct lack of ports.

In short, there are definitely things Apple can do to improve the next Mac mini – in whatever form that takes.

But it appears there might be a far bigger problem lurking beneath the skin of that aluminium casing.

According to iMore, some M1 Mac owners have received rather worrying health readings from their SSDs. Relating to the TBW (total bytes written) figure, the findings suggest that, under heavy use, some M1 machines won’t even last half a year.

Should we be worried? To find out, I decided to run some tests (yeah, I know – this is Mr ‘I Don’t Do Benchmarks’ talking here).

What’s all the fuss about?

The iMore article quotes a posting on the LTT forums.

“Some more professional users of the new M1 Macbooks are experiencing extremely high drive writes over relatively short time.

“The most severe cases have “consumed” about 10-13% of the maximum warrantable TBW value of the SSDs (given their capacity & using values for equivalent market-available NVMe drives).”

In layman’s terms, this means that under particularly heavy load, M1 Macs are spending far too much time writing to their SSDs. This is concerning, because that TBW figure is essentially an indication of how long a drive will last.

Every SSD has a maximum TBW value which gradually erodes the drive’s efficiency the closer you approach it. This has long been a challenge for manufacturers; for all the speed, efficiency and silence of SSDs, they do have a limited life span. Some refer to it as the built-in “time of death”, which is rather tragic, but also an unavoidable fact of modern computing.

I’ve received a few comments about this on my videos and blogs whenever I wax lyrical about how great the M1 chip is with such limited RAM. They point out that the measly 8GB of RAM in my M1 MacBook Air will simply wear the drive down over time, because so much additional pressure is put on the SSD to do the work of missing RAM.

These people absolutely have a point. But my response has always been the same: would Apple really sell a laptop that could potentially fall into disrepair before its standard warranty expires? Surely these kinds of concerns have been abstracted away from us thanks to advancements in software and the reliability of SSDs?

If there’s anything sinister behind the iMore report, maybe I’m wrong. There are suggestions that the issues could be software related (in so far as macOS needlessly writing to the drive when it should be doing something else), but the findings are worrying, regardless.

My tests

The tool I used to test the SSDs in my Macs comes from a company called Binary Fruit. DriveDx offers a limited free trial, which is ideal if you just want to quickly dip in and check the health of your drive.

The reports it produces are incredibly detailed. In fact, they’re far too detailed for a mere mortal like me, but there are lots of bar graphs and conversational language used to illustrate the shape of your SSD, so I can work with that.

I decided to run the test on the four Macs I have in my studio.

M1 Mac mini

Used since: January 2021

My M1 Mac mini currently runs my entire business. If you’ve read any of my previous articles on this machine, you’ll doubtless be bored of me rambling on about how wonderful it is.

But it is. Sorry.

I’ve used the Mac mini intensely since it arrived in January, including editing one or two 4K videos each week, often from the built-in SSD.

According to DriveDx, the mini’s 512GB SSD has written 5TB of data. Everything checks out fine. No need to worry. Yet.

M1 MacBook Air

Used since: December 2020

The MacBook Air offered my first experience of the M1 chip, and it knocked me sideways. It’s easily the most powerful laptop I’ve owned in such a small form factor. The battery is stellar (although, I still maintain that it’s the standby time which is most impressive), and the performance on offer belies its teeny-weeny eight gigabyte of RAM.

So, how has it faired since December, SSD-wise?

I opted for the base-level 256GB SSD in my MacBook Air, and, according to DriveDx, it has written just under 10TB of data in its time with me. It’s mildly interesting that it runs at a slightly lower temperature than the SSD in the Mac mini, but, regardless, everything checks out just fine.

Intel 16” MacBook Pro

Used since: November 2019

Why stop at the M1? I thought it’d make sense to test the SSDs on my Intel Macs, too – starting with the 16” MacBook Pro.

I specced this up to include a 1TB SSD, 32GB RAM and the fastest 8-core i9 CPU available at the time. For 18 months, it ran my business and was my editing powerhouse for both video and audio.

So, 15TB of data written, 158 power cycles, and zero issues found. Clearly, there’s plenty of life in the old dog yet.

Intel 27” iMac

Used since: March 2018

Ah, my beloved 27” iMac. By today’s standards, it’s pretty pathetic, spec-wise, but I still use it sparingly when I need to adopt a standing position (it resides on my standing desk, you see).

From 2018 to the end of 2019, it did everything for me and it’s the computer on which I finally realised my dream of making video production a form of income.

How has its tiny 256GB HDD fared during that time?

So, we’re 38TB of data writes in, and this is the only drive out of the four in my studio which is starting to show signs of wear. According to DriveDx, my iMac has chewed up 7% of its SSD’s life expectancy. But there’s clearly lots of life left.

The lesson

Maybe I need to be a little more cognisant of the way in which SSDs work and their relation to the choice of RAM in these M1 Macs.

The people who have found the most worrying numbers lying within their M1 SSDs are, I suspect, doing one of two things:

  • undertaking extremely intensive work on their M1 Macs (8K video editing, hours of intricate software development – that kind of thing); or
  • consistently running benchmarks to stress test the hardware.

There’s nothing wrong with either practice above, but if they’re undertaking what they consider to be normal work by their standards, it may well be that they’ve simply identified the M1’s break point. Perhaps they have discovered that, like any computer, it has a ceiling in terms of performance-per-buck – particularly if whatever they’re doing is eating away at that SSD so quickly. At that rate, it’ll never provide a decent return on investment.

My findings aren’t particularly worrisome. According to the DriveDx reports, we’re ok at Mark Ellis Review Towers; both my M1 MacBook Air and M1 Mac mini appear to be in good health, despite the latter being used consistently for 4K video editing.

My M1 machines are nowhere near as ‘used’ as those from which the reports emerged on the LTT forums. One user there revealed that 3% of his 2TB drive had already been consumed, but this was after 150TB of writes. But there was one metric missing from his report – the time in use. I’d love to see how quickly those 150TB of data were written. Was it over the course of months, weeks, or days?

So, I have one question for those of you who are far more clued up on this stuff than me: what are these guys doing with their M1 Macs? Get involved below, please – I want to get to the bottom of this.