Is defragmentation still necessary?

I can’t count how many older folks and certain syndicated radio hosts swear that defragging a hard drive will cure everything from viruses to world hunger. 

Back in the “old days” of 100 MEGAbyte hard drives, fragmentation was a serious problem that affected performance. However, with todays terabyte storage devices and up to 15,000 RPM speeds, and a very well-worn Windows operating system that was built to work with fragmented data, is regular defragmentation still necessary?

This question is related to three things, your operating system, file system and the physical medium (e.g. SSD).

In terms of operating system, Windows runs a scheduled task to defrag your file system once a week, so for end-users you shouldn’t ever need to defrag your disk.

The next variable is the file system itself. The old style FAT fragments much more quickly than NTFS due to differences in how NTFS allocates individual clusters and inodes, this is particularly noticeable for files which are written massively out of order, like torrent files for example, which download random pieces of the file out of order.

Multi-disk platters and inode “striping” allow multiple disks to be read simultaneously (modern file systems such as NTFS are optimized to do this) allows this to happen in parallel, reducing file-fragmentation reduces the number of seeks and high-density disks reduce spin-up time, but on modern SSDs when spin-up and seek time are almost zero - it probably doesn’t even matter if your files are splattered across the disk, other than making life easier for the hardware SSD cache if the fragments are less than an SSD cache page in size (which for NTFS and REFS they aren’t).

So in essence, the answer is no. You don’t need to defrag your hard-disk because on Vista and above it defrags itself, on NTFS and above it has relatively low fragmentation anyway, and on SSDs and above it probably wouldn’t even matter if it were fragmented.


Drive size and speed do not effect needing to defrag.  Track to track is the thing defragging helps the most, and so yes, you need to defrag.  Saying that, if you are just Joe Everybody, the built in Vista/W7 defragger is OK.  As someone else said, if you have V/W7, you ARE defragging all the time anyway, you just don’t know it.

If you are storing a lot of media on a drive, I’d get a real defragger like MyDefrag (it’s free), and create “zones” for the media.  Disable the built in one if you do.  All modern HDs can handle even the highest bitrate streams even on the inner tracks.  Once a month is fine with a good defragger.  (The V/W7 one runs daily, so that shows how good it is)

SSD’s only require a defragger if their garbage collectors (not TRIM) aren’t working.  (only 1st gen SSDs should need it, though leaving you machine on at the BIOS screen overnight, with the newer ones, about once a month will help them)

(BTW, I did 2 things to a free laptop someone was going to junk.  Ran CCleaner on it, then ran MyDefrag.  After that, they thought the laptop was great)

No, it will not speed up your system 10 times, cure viruses or world hunger, but your machine will run better.  But, you may think you have a virus, because you machine slows down, but all it needs is a defrag.

I thought you weren’t supposed to defrag SSD drives, at all, because it decreases their read/write life.

Hi yes that is true it will do more damage to a ssd than help it. You will notice if you have a SSD drive as a boot drive and use a mechanical drive for programs and storage, Windows 7 when you go to defrag and you choose Configure Schedule then Select disk’s the SSD drive will not be listed in the defrag screen, it is a known fact you do not defrag SSD drives. 

Only if the garbage collector doesn’t work well, which is what I said.  (first gen SSDs had very weak garbage collectors, which is why it’s easier to just run the defragger vs. waiting 3 or 4 days for the garbage collector to run the whole disk.)  I waited about 3 months (noticed the slowdown on writes) between defrags.

If the garbage collect is working, it does the defragging for you, but in a way that doesn’t hurt the SSD (much).  So, newer SSDs should not be defragged externally.