Solid state drive question.

[MJSWARLORD]

As you can see from my spec below i have 2 ssd in my pc.

i am aware that you should not defragment an ssd but does this mean that with installing and uninstalling software i will eventually have lots of scattered blocks of fragmented data that i cant compress to close up the gaps.

 

[Oussebon]

https://www.pcspecialist.co.uk/forums/showthread.php?53493-defrag-or-not&highlight=defragment

Apparently you can just let Windows take care of it.

 

[ubuysa]

The reason we have to defragment hard drives is because, as you say, the data gets spread all over the disk as files are written. The time to access data on a hard disk varies depending on how many fragments the file has been broken into and where on the disk surface each fragment resides. The reason for the variable access time is because we're moving metal; the read/write heads have to physically move over the surface of the disk to get at the wanted data. Defragmenting files (bringing all the fragments together in one contiguous block of data) massively reduces the amount of time the read/write heads spend moving to locate the wanted data thus improving access time.

A solid state disk is all memory (solid state memory, hence the name) and the time taken to access any block of data is exactly the same. This is because data access is done by electronic switching, there are no moving parts. So it really doesn't matter a scrap if a file is badly fragmented because we can get at any fragment just as fast as we could get at the data if it were in contiguous. There is thus absolutely no gain to be made by defragmenting an SSD, it simply doesn't make any difference. However, the defragment operation will move data around on an SSD and this uses up write cycles and has a tiny impact on the lifespan of the drive. Defragmenting an SSD therefore consumes a tiny part of the life of the drive and buys you absolutely no benefit in access time.

The concept of 'a gap' on an SSD doesn't really exist, simply because all data blocks can be accessed equally fast. In fact the way data is actually stored on the SSD is completely different to the way Windows thinks it is. The SSD management firmware creates the illusion that the SSD is some kind of hard drive with sectors, tracks, and cylinders when of course it's nothing of the kind. In addition, the SSD management firmware regularly moves your data around on the SSD so that each block gets used the same amount, this is called 'wear levelling' and it's done to ensure that one part of the SSD doesn't wear out before all the others. (Incidentally this data movement does not shorten the drive life. I have no idea why but it doesn't).

What this all means is that although we can think of an SSD like a very fast HDD, internally it's nothing of the sort!