why is defragging not really a thing anymore?

Question

I was born in 1973, got my first computer in 1994, defragging was part of regular maintenance. I can’t remember the last time I defragged anything, even though I have several devices with hard drives, including a Windows laptop. Has storage technology changed so much that defragging isn’t necessary anymore? Is it even possible to defrag a smart phone hard drive?

edit to add: I apologize for posting this same question several times, I was getting an error message every time I hit “post”… but from looking around, it seems I’m not the only one having this problem today.

In: 821

Answer 1

There are three major effects:

SSDs have generally replaced HDDs in many cases. SSDs do not have any seek time at all, and thus fragmentation does not matter*. In fact, SSDs internally remap themselves on write to balance the load to help ensure consistent wear on the drive – you can only write a given segment a fixed number of times before it goes bad**. Due to this, defragging an SSD not only provides no benefit, but it actually harmful to the drive.

Newer formatting methods, such as EXT4 and NTFS, have designs that tend to prevent fragmentation a lot better compared to the older methods like FAT. This drastically reduced the benefit of defragging a drive.

Operating systems also got smarter and started automatically defragging HDDs in the background. For Windows, I think this started around Windows XP. This means any HDDs you are using will get defragmented even if you don’t manually start the process.

It is also worth noting that fragmentation should only occur when you create or make a file larger after deleting or making one smaller by a segment. This often means backup disks will have very low rates of fragmentation.

* Well, there is still a tiny bit of overhead as the OS may need to make an extra disk request on a fragmented file, but that overhead will be on the order of nanoseconds compared to the tens of milliseconds of a HDD seek.

** As a note, for modern SSDs, this number is typically in the hundreds of thousands per segment, and possibly well into the millions. Remapping means you are unlikely to see problems for an additional order of magnitude as well.

Answer 2

There are three major effects:

SSDs have generally replaced HDDs in many cases. SSDs do not have any seek time at all, and thus fragmentation does not matter*. In fact, SSDs internally remap themselves on write to balance the load to help ensure consistent wear on the drive – you can only write a given segment a fixed number of times before it goes bad**. Due to this, defragging an SSD not only provides no benefit, but it actually harmful to the drive.

Newer formatting methods, such as EXT4 and NTFS, have designs that tend to prevent fragmentation a lot better compared to the older methods like FAT. This drastically reduced the benefit of defragging a drive.

Operating systems also got smarter and started automatically defragging HDDs in the background. For Windows, I think this started around Windows XP. This means any HDDs you are using will get defragmented even if you don’t manually start the process.

It is also worth noting that fragmentation should only occur when you create or make a file larger after deleting or making one smaller by a segment. This often means backup disks will have very low rates of fragmentation.

* Well, there is still a tiny bit of overhead as the OS may need to make an extra disk request on a fragmented file, but that overhead will be on the order of nanoseconds compared to the tens of milliseconds of a HDD seek.

** As a note, for modern SSDs, this number is typically in the hundreds of thousands per segment, and possibly well into the millions. Remapping means you are unlikely to see problems for an additional order of magnitude as well.