3.9TBW on a 2mo 16" MacBook Pro M5 Pro 48GB 1TB

[Ploki]

I didn't page out a lot, couple of GB all i had it a few times.

i didn't do migration - set it up as new.

I have 49HR of power on time and 3.9 TBW

My external i've been using for 2 years has 5.3TBW and 4500HR of power on time.

I find this bizzare, i don't get it.

 

[Bigwaff]

What software are you using to read these metrics?

 

[Ploki]

What software are you using to read these metrics?

DriveDx

 

[benholt]

one thing worth pointing out — "Data Units Written" on your internal is dominated by stuff that doesn't feel like usage. Local TM snapshots (tmutil listlocalsnapshots / will show them), Spotlight reindex after each OS point update, iCloud sync of Drive/Photos, Xcode simulators if you have any. My M2 Ultra Studio averaged ~40GB/day the first few weeks and settled around 15/day with light use.

Also DriveDx is reading the raw NVMe counter which includes write amplification — the OS asks for 1GB, the controller physically writes ~1.3-1.5GB. That gap is why external drives (mostly big sequential writes) always look cleaner per hour than a boot volume getting battered by tiny random writes.

 

[bzgnyc2]

I didn't page out a lot, couple of GB all i had it a few times.

i didn't do migration - set it up as new.

I have 49HR of power on time and 3.9 TBW

My external i've been using for 2 years has 5.3TBW and 4500HR of power on time.

I find this bizzare, i don't get it.

It's a little high for a boot drive but maybe normal based on what you are doing. My MacBook Air 2020 reports ~ 22 TBW over 805 power on hours (which seems low so assuming that doesn't count the time when macOS puts the SSD to sleep during the day as well as the night), which is about 1/3rd the rate of yours and yours is likely dominated by initial configuration usage.

I use mine mainly for productivity type work though occasionally use it for some high write activity / dev / moving large data sets around / etc.

Unfortunately macOS has generally gotten worse with regards to writes during boot. I saw a large jump in writes moving from Catalina to Monterey. I was annoyed that Catalina wrote a few GB out of the gate after every boot for no obviously good reason. On the above computer, "powerd" was writing out 8GB on every boot under Monterey and overall averaged more writes per day. Not seeing that issue with "powerd" on Sequoia but otherwise generally seems to average more writes per day than Catalina.

This is something I think Apple could clean up. 0 writes on boot is unrealistic but I would make every write on a normal boot justify itself. I bet they could get it down to MBs if they tried, and it would only reduce the risk of corrupting files.

In any case, we have the macOS we have. If you want to monitor it, I would separate boot writes from average daily writes and then track the latter for a few days. You can use Data written under Disk in Activity Monitor to get a quick number. Quick check after boot to get your initial number and then see how it goes up each day. It is a system total though so having an external drive connected will throw off the numbers. Doing the same from DriveDx will let you isolate to just the boot drive.