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

NavyLCDR said:

First question software error. Second question no. Google how a SSD works.

And mine?

NavyLCDR said:

Actually, it looks like I was mistaken. I was confusing Trim, an OS function, with garbage collection, an SSD firmware function:

What is SSD TRIM? - Definition from WhatIs.com

Thank you. I read the link, and it makes perfect sense.

Anibor said:

I have noticed another anomaly in this process:

Task Scheduler reports a successfully executed "optimization" operation, but it corresponds to a "ScheduledDefrag" task, not to the "WesternDigital_SSD_TRIM_xxxxx" task. The operation also appears as executed over the SSD in the "Optimize Units" window. There is only a SSD installed, no HDD.

This one? The word "Defrag" is a holdover. Should read "Optimize" to avoid the confusion. Maybe MS will change the wording some day. Or not.....

Anibor said:

As I posted above, there is a task called "WesternDigital_SSD_TRIM_xxxxx" which seems to correspond to the real TRIM operation, and I have seen executed before.

Moreover, the "ScheduledDefrag" task was executed yesterday at 17:23 p.m. Several hours before, at about 2:00 p.m, I had done a manual TRIM from Windows, because 28 days had passed since last execution, and an "optimize required" warning was showing. So, another TRIM was not necessary at all.

I understand now, that entry, "WesternDigital_SSD_TRIM_xxxxx", must have been added by some software that came with your WD drive, since it's not a standard Windows entry.

NavyLCDR said:

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.

This is correct. Most newer SSD's TRIM themselves during idle periods, so you really don't have to do anything.

FWIW.

Compumind said:

This is correct. Most newer SSD's TRIM themselves during idle periods, so you really don't have to do anything.

FWIW.

From the link Navy provided. Seems the "garbage collection" is what can run during SSD idle periods, not the TRIM.

"Garbage collection may wait for lulls in drive activity to initiate the process, sometimes leaving pages that are obsolete in the SSD."

"TRIM eliminates any unnecessary copying of discarded or invalid data pages during the garbage collection process to save time and improve SSD performance."

So it appears TRIM is a useful function, initiated by the OS to the controller.

f14tomcat said:

From the link Navy provided. Seems the "garbage collection" is what can run during SSD idle periods, not the TRIM.

Yes, some clarification is in order. I had it the other way, oops!

Garbage Collection is run at idle, then TRIM will be invoked by the OS when/if scheduled.

Using TRIM, an SSD is not forced to save pages belonging to deleted files. TRIM is not an alternative to garbage collection.
It is a bit different. It actually works closely with the SSD's garbage collection algorithm to more properly mark those pages as "stale."
Now, you don’t need TRIM for garbage collection to work but TRIM makes an SSD’s built-in garbage collection routine much more efficient.

That's it. Now, breakfast.