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I've read on some websites that it's bad to defrag an ssd. But I'm reading on this website now and one person was like "You didnt do any harm its just not necessary to defrag it." I feel like that's wrong since every other website I've read says it will damage the ssd.

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marked as duplicate by ChrisInEdmonton, Keltari, music2myear, Matthew Williams, Kevin Panko Oct 3 at 16:31

This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.

    
In short, SSD will still suffer from fragmentation. But SSD will also suffer from moving of files on the process of defragging the SSD. SSD has a write cycle limit, so the more often you write / rewrite into the SSD, the quicker it is to degrade the SSD. SSD is pretty fast as it is, so even in a fragmented condition, it may still outperform normal HDD without any fragmentation. (May. Testing is required) –  Darius Jan 1 at 10:50
    
This question is a dupe. I have also said this before as well... There is no point in defragging a SSD, since SSDs intentionally fragment their data for wear leveling. –  Keltari Oct 2 at 19:35

5 Answers 5

Mostly pointless, but of course there is a penalty to pay in that you are shortening your SSD life cycle. There is an excellent PCWorld magazine article, where the guy did amass some independent, and original, evidence. He reaches the conclusion above by comparing the accomplishments of 4 programs, otherwise quite successful in defragmenting HDDs, not SSds.

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No, you should not defrag an SSD. And performing one will actually reduce the life of your drive. All of the SSD manufacturer’s know of this problem and they have come up with an optimization technique with the use of the TRIM command.

Currently, with HDDs and SSDs, if you delete some data on the hard drive, the operating system does not actually remove the content from the disk, it just deletes the pointer to the address and therefore “deletes” the data. That’s probably why you’re heard of secure delete or government security file deletion, which actually overwrites the deleted data with gibberish so no one can use advanced tools to read data later on.

This issue of data not actually being deleted is what causes the lifespan of SSDs to be reduced. If the drive knew which areas of memory didn’t contain any important data, it could simply re-use it for new data. The TRIM command is supported by the latest SSDs and will optimize the hard drive so that it reduces the number of writes/deletions and therefore extends the life of your SSD significantly.

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"Currently, with HDDs and SSDs, if you delete some data on the hard drive, the operating system does not actually remove the content from the disk" This is what TRIM is supposed to fix. It allows the OS to mark an area as disposable, so an SSD can erase it at its discretion to speed up future writes to that area. –  nitro2k01 Jan 1 at 11:05

The issue with SSD's is they have a limited guaranteed 'read/write' lifetime (as compared to say a platter based hard drive), so the more data is written to the SSD (as would be the case with a defrag operation), you are decreasing the effective lifespan of the SSD. Mind you typical lifespans of SSD's these days range in the couple of year category (assuming constant writing).

The point of defragging a standard hard drive is the way they physically work: when data is written to the drive, it is possibly spread about the disk, and since a head has to move across the platters to recover a file, if it is 'spread out' on the physical disk, it will take more time to read the entire file. This is not true of SSD's however because it's the same latency to read the file from wherever it is on the flash.

hope that can help.

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I almost fully disagree with everyone.

Yes, I agree with: how more writes and stuff, decreases your lifespan of SSD

But, a big BUT

  • people recommend also, that you don't move your internet temporary folders and cache folders, from SSD to an HDD. Why ? I don't understand.

Every site you view creates new cache files on your ssd. Then you use a tool like CCleaner to remove them again. That's a lot of writes done on your ssd.

Now we are getting to the point: Never do a defragmentation on your ssd.

If you never do it, like me in the past, what are the results ... ????

Your SSD is so heavenly fragmented, that it slows down your windows startup. I've seen it with my own eyes.

In the beginning startup time: 17 seconds. After a few years: 45 seconds and increasing !!! Even my READ and WRITE gets slower.

From that moment on, I've decided to defrag only, the fragmented files. (so not everything) Only what's fragmented. Free program "Defraggler" has this option: by selecting the fragmented files.

I did a reboot of my pc after that = startup time => 18 seconds again !!! Yes: one second less, but I've installed many new things also in all those years.

End conclusion: Do only a defrag on the fragmented files, 2-3 times a year.

Specially if your cache temp internet files are also stored and removed on your SSD.

Do you really think, that those 2-3 times will make a huge impact on your lifespan ? While daily read and write: internet files.

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The speedup is likely not the result of defragmenting your files but rather the fact that defraggler runs TRIM: piriform.com/blog/2013/10/22/defraggler-v216 –  ChrisInEdmonton Oct 2 at 19:04
    
Say what you want, wait till 50% of you're SSD is fragmented. –  Jack B. Oct 2 at 19:08
    
"your", not "you're". And you have not established that your speed improvements were unrelated to TRIM. It's certainly not impossible that your speed improvements were due, at least in part, to defragging, but it's really unlikely due to the way the NAND chips work. It's just as fast to pull data from the beginning and then immediately from the end of the SSD, unlike on a mechanical disk. That's why defragging helps a mechanical disk. –  ChrisInEdmonton Oct 2 at 19:11

Traditional spinning hard drives have a metric known as Access Time (or Seek Time, which is a slightly different measurement) that refers to the average amount of time it takes for the drive armature to physically reposition the heads so that they can begin reading data from a given sector of the disk (it may be more or less depending on how far the heads have to travel). It should be noted that this latency is measured in milliseconds (thosandths of a second) and is incurred every single time the heads have to be repositioned.

The whole purpose of defragmentation is to arrange the files in such a way as to make them more or less sequential, so that the heads do not have to be repositioned as much in order to read a file.

SSD's do not have heads that need to be moved, nor do they have spinning latency. As a result, the access time for every cell in the matrix is equal, and is measured in nanoseconds (billionths of a second). Even if a file is very heavily fragmented, the increased latency to read it is imperceptibly small. Defragging will not improve performance to a noticeable degree.

Also unlike traditional spinning hard drives, the individual cells in an SSD have a limited number of write cycles before they "wear out". SSDs employ a wear-leveling algorithm to spread out writes to extend the life of the drive. Relocating the same data to a different area of the flash cells waste those write cycles. In this case, defragging can actually reduce the lifespan of the drive.

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