SSDs and defrag, if not unnecessary, harmful?

[zCypher]

Howdy y'all,

Just curious about this as I realized defrag was enabled by default in Win8 which surprised me. It said my SSD hasn't been "optimized" in 15 days. All my other drives (non-SSD) were presumably optimized recently. All drives showed 0% fragmentation.

I just disabled it. If I ever have any concern about fragmentation, I can always open the tool and check it out.

Could this have caused any damage to SSD? I haven't noticed any symptoms, and I don't think I have anything to worry about, but maybe some more well-informed people can confirm or enlighten.

Thanks

[hhhd1]

Windows 8 do not defragment SSDs, optimization is just sending TRIM command to free spaces.

Windows 8 is smart enough to optimize SSDs and HDDs differently

[corkyg]

The accepted optimization of SSDs focuses on white space consolidation only.

[Emulex]

its far more likely to recover a file with 1 segment than 6000

[Nothinman]

Originally Posted by Emulex

its far more likely to recover a file with 1 segment than 6000

Which shouldn't even be a consideration because you should have some kind of backups, even if it's something cheesy like previous versions on Windows.

[bbinnard]

I'm not so sure that it is.

On a HDD Windows reads the FAT to determine which parts of a file are where. On a HDD the FAT is a table that identifies where files are. But on an SSD the SSD firmware relocates blocks of data based on where is thinks is best. Moreover, it (the SSD firmware) even relocates blocks of data when it sees this will help conserve space on the SSD.

Windows is unaware of anything the SSD firmware does; all Windows sees is the data presented to it by the firmware. So how can Windows have any idea where data is actually located on the SSD?

My sense is that all defragging an SSD does is move data around on the SSD; the actual physical location is determined not by Windows, bu by the SSD firmware.

[Smoblikat]

Originally Posted by bbinnard

I'm not so sure that it is.

On a HDD Windows reads the FAT to determine which parts of a file are where. On a HDD the FAT is a table that identifies where files are. But on an SSD the SSD firmware relocates blocks of data based on where is thinks is best. Moreover, it (the SSD firmware) even relocates blocks of data when it sees this will help conserve space on the SSD.

Windows is unaware of anything the SSD firmware does; all Windows sees is the data presented to it by the firmware. So how can Windows have any idea where data is actually located on the SSD?

My sense is that all defragging an SSD does is move data around on the SSD; the actual physical location is determined not by Windows, bu by the SSD firmware.

The reason it is harmful is because of (at the very least) the unnecessary amount of writes.

[Nothinman]

Originally Posted by bbinnard

I'm not so sure that it is.

On a HDD Windows reads the FAT to determine which parts of a file are where. On a HDD the FAT is a table that identifies where files are. But on an SSD the SSD firmware relocates blocks of data based on where is thinks is best. Moreover, it (the SSD firmware) even relocates blocks of data when it sees this will help conserve space on the SSD.

Windows is unaware of anything the SSD firmware does; all Windows sees is the data presented to it by the firmware. So how can Windows have any idea where data is actually located on the SSD?

My sense is that all defragging an SSD does is move data around on the SSD; the actual physical location is determined not by Windows, bu by the SSD firmware.

That's irrelevant because the same can be true of any type of storage. There's no guarantee that the firmware on a spinning drive isn't lying about the location of data either, in fact that's exactly what it does when it relocates a bad sector to it's spare pool.

[HeXen]

According to MS, W8 doesn't actually defrag SSD's, it just does some kind of Trim thing on them. Key word noted on it says "optimize HD's"
Wish i could find the link to that.

[taltamir]

Originally Posted by bbinnard

Windows is unaware of anything the SSD firmware does; all Windows sees is the data presented to it by the firmware. So how can Windows have any idea where data is actually located on the SSD?

My sense is that all defragging an SSD does is move data around on the SSD; the actual physical location is determined not by Windows, bu by the SSD firmware.

That is correct, defragging an SSD simply randomly shuffles data around.

The SSD controller actually defrags the free space internally as a side effect of the process of clearing cells to prepare them for a write (which is the main purpose of trim; as it avoids read-modify-write cycles) and it does so based on knowledge of what sectors contain data and which contain junk. Something it generally only finds out via receiving trim command for junk sectors.

As others have said, windows 8 defragmenting tool will send trim to the SSD instead of defragging it.

[zCypher]

Awesome replies from everyone, thank you! Very interesting, and so I clearly have nothing to worry about heh.

[Puffnstuff]

I had to disable defrag on norton and perfect disk 10 on my ssd to prevent them from doing it to my drive. Most ssd's have garbage collection routines to reduce clutter.

[Fernando 1]

Originally Posted by hhhd1

Windows 8 do not defragment SSDs, optimization is just sending TRIM command to free spaces.
Windows 8 is smart enough to optimize SSDs and HDDs differently

This is only valid, if Win8 has detected the SSD as SSD.
If the Optimizer should have listed the SSD as HDD, you should not run the Optimizer!
Sometimes it helps to run the Windows Experience Index before going to run the Optimizer.

[Nothinman]

Originally Posted by Puffnstuff

I had to disable defrag on norton and perfect disk 10 on my ssd to prevent them from doing it to my drive. Most ssd's have garbage collection routines to reduce clutter.

That's because you wasted your time with 3rd party defrag tools. Garbage collection isn't about reducing clutter, it's about wear leveling and making sure the memory lasts as long as possible.

[Insert_Nickname]

Originally Posted by Nothinman

That's because you wasted your time with 3rd party defrag tools. Garbage collection isn't about reducing clutter, it's about wear leveling and making sure the memory lasts as long as possible.

Well said...

When you have equal access time across the entire drive, defragging is kind of pointless...

[taltamir]

Originally Posted by Nothinman

That's because you wasted your time with 3rd party defrag tools. Garbage collection isn't about reducing clutter, it's about wear leveling and making sure the memory lasts as long as possible.

that and also about having enough pre-deleted sectors to prevent a read-modify-write cycle.

The fact it also consolidates free space to a point (a common option in defrag tools) is a side effect not the actual goal; caused by the fact that a large amount of contiguous cells have to be erased at the same time.