Is it bad if a SSD is too fragmented?

derek10 · 13 Aug 2016

I know this is a old question but I can't find proper answers there and here.
I run Mydefrag (I have it because I have 3 mechanical hard drives) and checked my SSD out of curiosity and it's all yellow (fragmented), seems that at least 80% of all files are fragmented.

I know that SSDs don't need to be defragged because they have way less seek latency than HDDs and shortens its lifespan, but can performance be somewhat reduced in a heavily fragmented file system, I say, Windows needs to locate every file fragment and that needs CPU?

Thank you

Cliff S · 13 Aug 2016

Windows just thinks it's fragmented, because the SSD's controller "Lies" to Windows to make it think it's a spinner.
For example, if Windows expects the boot files to be at the outside of the disk, so the controller say's "yup, that's exactly where I placed them(fingers crossed)", but there is no disk, just cells.
So over time Windows thinks the SSD is fragmented, when it's not. Data is always placed in whatever cells are free, until trim is run, then they are place in blocks together, so the controller won't have to search all the chips.

Another words, in short, only the SSD's controller knows where the data actually is.

derek10 · 13 Aug 2016

So it's simply how the controller reports to Windows and not the real state of fragmentation

Thank you for you excellent answer :)

Cliff S · 13 Aug 2016

derek10 said:

So it's simply how the controller reports to Windows and not the real state of fragmentation

Thank you for you excellent answer :)

You're welcome:)

CountMike · 14 Aug 2016

HDDs (spinners, mechanical) also "Lies" to OS, logical and physical sector placements are not same.

Mystere · 14 Aug 2016

Fragmentation is not strictly just about where blocks live on the disk.

Another aspect of fragmentation is fragmented directory entries and the MFT. When these become fragmented, they use up more space than is necessary, and cause extra lookups for directory scans. Thus, over time, it takes longer and longer to find any given file. In extreme cases, the filesystem can actually run out of entries and cause other issues.

This is why the Windows disk defragmenter will, on occasion, do filesystem defragmentation and cleanup on SSD's, in addition to running TRIM requests.

You should only use an SSD aware disk defragmenter, such as the built-in Windows Defrag. It does a fine of making SSD's the most efficient they can be.