Fragmentation - SSD vs mechanical drive

[Lonyo]

Obviously having a heavily fragmented mechanical hard drive reduces performance because it has to go to various parts of the disc to get the file, if my understanding of file fragmentation is correct.

SSD's have very low access times and very good read speeds for the most part - do they get affected by having a heavily fragmented drive, or do they just continue as normal?

 

[octopus41092]

On SSDs, there is no need for tracks or sectors. The underlying memory locations of the SSD are organized into clusters which the operating system can work with just as it does the clusters on an HDD. Since there are no physical sectors underlying the clusters on an SDD, files do not become fragmented on the sector level at all. Files can still be fragmented as the clusters occupy data locations that are physically apart from each other, but the effect of even that fragmentation has nowhere near the affect of cluster fragmentation on an HDD. It takes much less time for an SSD to electronically change the memory address to the next cluster in a file than it does for an HDD to move the heads and wait for the cluster's sectors to rotate under the head. You should hardly ever need to defragment an SSD. If it makes you feel better, you could do it once a month to eliminate cluster fragmentation, but you'll be hard put to notice any ill effects if you miss several months.

 

[imported_wired247]

the real question is, will defragmentation software be able to properly defrag an SSD? If it treats the SSD like a real hard drive it may not be doing the SSD any favors. If the defrag software assumes you are using a real hard drive it will try to "move out" certain files and "move in" other files.

I could imagine improving seek times by defragging an SSD so that files are placed on the same column. Correct me if I'm wrong but I believe it is faster to address column X and then read sequentially off of row A,B,C,D, etc. rather than have to jump around to different row+columns all the time.

 

[Lorne]

There is no affect what so ever of file fragmentation on a SSD, Each bit is accessed the exacly the same no matter its location, A 100% fragmented drive would show no change in access or speed as one that was not fragmented at all.
Also SSD drive dont slow down as they get filled, Platter drives will decrease in speed as it fills the inner radius a test that is not done in most benchmarkings anymore.

You can defrag SSD's, Ive defragged pendrives/memorycards and You can even defrag static memory drive, Not that it really helps.
The only reason I can think of to defrag a SSD is it looks good on some defrag programs and for some freak reason you get corruption theres a less chance of crossthaching, But I doubt it will be that simple.

 

[Foxery]

It's even simpler - a fragmented hard drive is slow because the mechanical parts are moving all over the place. An SDD has no moving parts; random access happens at exactly the same speed no matter where the data is located.

 

[nerp]

Metaphor:

An anteater's nose as opposed to a whale's baleen.

 

[taltamir]

defragging an SSD just wastes its life. Electricity, and the life of other components (and your time).
there is no reason to defrag an SSD because it takes roughly the same amount of time to access any specific location on the drive.

Actually defragmenting a REGULAR hard drive is a bad idea too. it wastes its life and gives minimal benefits.