> I Think HD sentinel is using power on time to lower the health.
I can confirm that this is NOT TRUE of course.
Please check the text description. It shows the source of the health: if problem(s) found, then they may cause the lower health.
Or if there are no problems (no bad sectors or so) then the health is determined by an attribute, which suggests the generic wearout of the SSD.
This is independent from Hard Disk Sentinel, the SSD calculates and provides this value, based on the wearout.
Even if the drive has lower total amount of data written, the type of data written may be important.
For example frequently updating smaller files may cause much bigger overhead and can cause higher wearout (=lower health) even if the total amount of written data is lower.
If you use Report menu -> Send test report to developer option, I'd be happy to check the status of the SSDs, verify and compare their values.
But again just to make sure: the power on time value is NOT used in determining health (for any device).