Windows 10: SSD with a HDD installed not being trimmed automatically, why?

I apologize if this thread appears a bit odd. I reconstructed this after deciding I shouldn't continue in another thread that is somewhat unrelated. That thread was located here;

Disk Optimization Turns Off...

Recently, I've noticed that my SSD is not getting trimmed on the same schedule as my HDD is defragged. I have my OS with a small reserved section for future use on an SSD and data on a HDD with the defrag schedule set to weekly.

The HDD (D: Data & F: old Windows) and the reserved section on the SSD (L: Linux) appear to get defragged or trimmed on a weekly schedule as configured although they appear somewhat staggered.

I have seen the same thing on my SSD. The small data section got trimmed on a weekly schedule same as the HDD, however; the OS section of the SSD did not get trimmed. It was necessary to run trim manually.

I am curious dalchina, on your SSD with partitions, was the area without the OS trimmed on the weekly schedule, similar to the HDD?

It appears that the OS section on an SSD is not being trimmed on schedule. Odd!

The mystery that I'm curious about is simply that it would appear that C: on an SSD gets trimmed on schedule when there's only the single drive installed. When more than one drive is installed, C: on the SSD does NOT get trimmed without manually running the trim action.

I have no great concerns, only curiosity. So far this seems to be happening on both 1809 & 1903. Has anyone else experienced this feature or anything different with trim behaviour?

:)

 

SSD with a HDD installed not being trimmed automatically, why?

Then I am confused. Maybe Windows is simply reporting it wrong.

SSD in question. All below partitions in the Windows Optimize screen are on the same physical SSD.





Before Optimize of the partition "Virgin RTM":





After Optimize of the partition "Virgin RTM":





I only optimized the one. Closed Windows Optimize app and re-opened.
Shows the one I just did, time stamp is correct. Other two seemed to be untouched, unaltered.

 

SSD with a HDD installed not being trimmed automatically, why?

SSDs don't allocate physical sections of the drive to partitions the way that HDDs do. When an SSD is trimmed, the only command sent to the firmware is to run the trim process. Due to the way SSDs store data in the physical cells of the drive, it is impossible to specify only a single partition to be trimmed. Every cell that contains obsolete data must be processed and any cell in the drive can contain data from any partition.

 

SSD with a HDD installed not being trimmed automatically, why?

COOL!

So it would appear that scheduling only applies to defrag and not trim on SSD's, interesting. Thanks for that tidbit Mooly.