And I explained to you, your understanding is incorrect.
An SSD needs so close to the same amount of time to read a linear file compared to a fragmented file that the difference is imperceptible. 0.1ms per seek, less than 1/1000th of what you are claiming.
To directly copy from Crucial's website:
Should I defrag my SSD?
The short answer is this: you don't have to defrag an SSD.
To understand why, we first need to look at the purpose of defragmenting a drive. Defragging ensures that large files are stored in one continuous area of a hard disk drive so that the file can be read in one go. Mechanical drives have a relatively long seek time of approximately 15ms, so every time a file is fragmented you lose 15ms finding the next one. This really adds up when reading lots of different files split into lots of different fragments.
However, this isn't an issue with SSDs because the seek time are about 0.1ms. You won’t really notice the benefit of defragged files — which means there is no performance advantage to defragging an SSD.
SSDs move data that's already on your disk to other places on your disk, often sticking it at a temporary position first. That's what gives defragmenting a disadvantage for SSD users. You’re writing data you already have, which uses up some of the NAND's limited rewrite capability. So, you get no performance advantage whatsoever, but you are using up some of the limited rewrite capability.
My understanding is not incorrect, please stop assuming that because your understanding is shallow (using consumer-grade information as a reference makes that obvious) that that of others must be as well.
I never claimed that you should defragment your SSD, I just pointed out that fragmentation is still an issue on SSDs, which is a true fact.
Reading a large fragmented file can be 30% slower than if it is not fragmented. Now if you don't think that's significant, you're just silly.
Well, then, instead of being an abrasive speaker, you should point me to sources that back up your claim.
I was able to find a page that talked about write amplification and read speeds decreasing when files are overly fragmented on SSDs, but that was 7 years ago and technologies have improved dramatically since then, not to mention that the effect was found in files split into four hundred thousand pieces, which indicates the slowdown may have been more on the in-drive ASIC not having the throughput needed to deal with that many fragments than with the actual read/write of the disk itself.
Where's your recent (last 4 years) paper or article that indicates that file fragmentation has anything more than a negligible affect on read/write speeds in an ssd?
If you can't put up, then nothing you say matters.
This is pure logic, no need for any experiment or benchmark.
Fragmented files require reading more blocks. The exact scheme depends on the filesystem used. The 30% figure came from an estimation of the ext4 worst case vs best case of number of reads needed.
An SSD needs so close to the same amount of time to read a linear file compared to a fragmented file that the difference is imperceptible. 0.1ms per seek, less than 1/1000th of what you are claiming.
To directly copy from Crucial's website:
Should I defrag my SSD?
The short answer is this: you don't have to defrag an SSD.
To understand why, we first need to look at the purpose of defragmenting a drive. Defragging ensures that large files are stored in one continuous area of a hard disk drive so that the file can be read in one go. Mechanical drives have a relatively long seek time of approximately 15ms, so every time a file is fragmented you lose 15ms finding the next one. This really adds up when reading lots of different files split into lots of different fragments.
However, this isn't an issue with SSDs because the seek time are about 0.1ms. You won’t really notice the benefit of defragged files — which means there is no performance advantage to defragging an SSD.
SSDs move data that's already on your disk to other places on your disk, often sticking it at a temporary position first. That's what gives defragmenting a disadvantage for SSD users. You’re writing data you already have, which uses up some of the NAND's limited rewrite capability. So, you get no performance advantage whatsoever, but you are using up some of the limited rewrite capability.
https://www.crucial.com/articles/about-ssd/should-you-defrag...