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Andrey84

macrumors 6502
Original poster
Nov 18, 2020
406
302
Greater London, United Kingdom
While checking on my SSD's health, I was surprised to see the Power Cycle Count of 70,619 yesterday. I was even more surprised to see it increase by 21 to 70,640 today, even though total pick-ups for today and yesterday were 9, and I've disabled 'put hard disks to sleep when possible' yesterday.

It's a Mid 2015 15" MacBook Pro 11,4 (i7/16/512).

As you can see, I don't think the disk sleep setting has any effect, as I got 21 new power cycles still over the 24 hours. 21 appears to be very close to the daily average for power cycles over the lifetime of this machine: 21 x 365 x 8.5 = 65,152.5.

I expect it to have been used professionally until 2019, when I bought it, and since then I only used it casually (not every day).

I know this statistic probably doesn't really matter, and the laptop will easily live another 5-7 years, to the point of becoming fully obsolete, and SSD will still be fine. However, this SMART indicator is showing 30%, which is worrying.

Why does it power up and down so often?

Do you have any ideas how to reduce the daily increase in power cycle count?

Screenshot 2024-01-07 at 15.46.34.png


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You're worrying about the wrong metric. Watch ID 178, your Wear Leveling Count. That's at 89%, indicating that in the 9 years this machine has been in operation it's doing absolutely fine.

I have a feeling these power cycles are possibly related to the Energy Saver (or Battery) setting for "Put hard disks to sleep when possible". Seems like putting a drive to sleep to save power might count as a "power cycle"?
 
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You're worrying about the wrong metric. Watch ID 178, your Wear Leveling Count. That's at 89%, indicating that in the 9 years this machine has been in operation it's doing absolutely fine.

I have a feeling these power cycles are possibly related to the Energy Saver (or Battery) setting for "Put hard disks to sleep when possible". Seems like putting a drive to sleep to save power might count as a "power cycle"?
Ok, thank you. Do you think the SMART setting is showing this metric as 30% because these percentages are still based on mechanical disks?
 
Ok, thank you. Do you think the SMART setting is showing this metric as 30% because these percentages are still based on mechanical disks?
That I do not know. Someone more knowledgable will have to chime in on that. It's worth looking into, but I think the Wear Leveling Count is the one to really watch.
 
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Ok, thank you. Do you think the SMART setting is showing this metric as 30% because these percentages are still based on mechanical disks?
I’d guess so. I don’t think there’s any data out there on cycle counts on an SSD or if there’s any point to them.
 
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