Defrag ssd


Apr 28, 2008
Don't. Ever. Period.

The whole point to defragging a drive is to put the data into sequential order so that it reads faster. This happens because the drive head doesn't have to move all over the disc to get to the data that is out of order.

In an SSD there is no head to move around, and every sector of data reads at the same speed. No need to defrag.

In fact defragging can be damaging to your SSD. Each cell in an SSD can only be written to so many times. There are algorithms in the SSD controller that help to spread the data out over the entire drive so that you are not writing to the same cell over and over again while there are other cells that don't ever get written to. This is called wear-leveling . A defrag is constantly reading and writing data to move it around the drive and can severely impact your wear leveling.



All the information above is excellent.

A few extra things to consider:

Regular Hard Disk Drives use what's called a "platter" inside of the HDD. The platter is a circular magenetic disk that contains information on "tracks" which are circular (and go around the platter). By defragging a HDD, you put the information in a relatively "straight" line/same area on the platter. If a HDD is heavily "fragged" all that information (OS, program files, etc) would be in random places on the tracks and on the platter, slowing the loading process as the head reader in the HDD has to "travel" further than if the system was de-fragged.

By design, SSD's install information in a "fragmented" way. However, each nand cell can be read/written to, so even though the information is "fragmented", it will still read much faster than a HDD. For this reason you should not "defrag" a SSD. It is meant to be fragmented. Forcing an SSD to defrag would make it continuously read/write and move the data pointlessly, basically lowering the lifespan of the SSD.

SSD's usually contain anywhere from 4-16 flash chips on them - and each chip can be read/written to, versues a hard drives single head that can only read information in a "straight line" on the platter.

Hope this helps.


Jan 10, 2010
I don't have an SSD on my PC...
But I have installed an SSD on a friend's computer and to avoid him "too many writes"
I simply changed the defaults for:
. documents
. downloads
. music
. pictures
. video
. programs
to a hard drive minimizing the write/erase on the SSD.

game junky

Feb 2, 2012

+1 - don't defrag a solid state.
The general consensus is that ssd defragmentation is not necessary and might even be harmful. If we go back far enough we find defragmentation designed for hard disk drives did in fact reduce performance and an ssd's lifespan.

There was a problem because solid state drives do suffer from file system fragmentation. Bit and pieces of a data file wind up being stored all over an ssd. The end effect is that a single request for a data file is transformed in mutiple requests for bits and pieces of the file. It is commonly referred to as the I/O multiplication effect. It is most noticeable during and ssd's write cycles.

What was needed was a solution to the defragmentation vs. shortened lifespan dilemma. In September 2008, Apacer introduced an optimization algorithm that solved the problem. It was a compromise and the craziest thing about it is the algorithm caused a partial defragmentation that actually helped extend an ssd's life span.

Jumped forward a few years and we now have utilities like iolo's System Mechanic Pro that include ssd optimization which is different from hard disk drive optimization.

Bottom line - DO NOT USE disk defragmentation designed for a hard disk drive. USE disk defragmentation specifically designed for an ssd.


Jan 6, 2008

I use Diskeeper with HyperFast.
Kursun - I am sure the utility works quite well. However, under the benefits tab on the product page you linked to I found some exaggerated claims:

"Enables 6 times faster reads & 20 times faster writes"

With modern ssd's that would be impossible.

I haven't seen a technical review. I know back in late 2008 and early 2009 there was quite a bit of controversy. Tom's Hardware published an article that was skeptical of ssd defragmentation/optimization. Unfortunately there was no testing. OCZ published the results of a Diskeeper with HyperFast test in their ssd forums indicating there was some improvement in ssd's that had been in use for some time but nothing like the advertising claimed. At the same time Intel Engineers claimed there was no benefit to defragmenting/optimizing ssd's because the ssd's were so blazing fast.

Three years have gone by and there is very little factual information available. The only thing I know for certain is that Apacer developed a defragmentation algorithm that is actually a partial defragmentation. Newer information seems to indicate that some of the utilities do not actually perform a defragmentation. Instead they "optimize" an ssd.


Apr 22, 2009
Thanks JohnnyLucky. I suspect it's best to leave the SSD optimization to the SSD itself... that's what the controller & firmware are for... and the SSD should know best.


Jan 6, 2013
I have one case in which to defrag an SSD: when your SSD has like 20.000 files in 160.000 fragments, some of them in as much as 4.000 fragments each, and you want to make a disk image to a conventional HDD (like, for backup purposes).

In that single case, running defrag is waaay faster before you make the image than after.

Rest of the time, just let it be.


Nov 28, 2012
After restoring an image (e.g. Clonezilla) of a partition or whole drive to a Solid State Drive and have confirmed the drivers are working I'd suggest leaving it at the Windows login screen for 30 minutes (set the power saving just in case) and coming back to the unit after it has gone to sleep.

When modern SSD's are idle they rearrange their own data for maximum performance and wear-leveling. Similar to Garbage Collection in Java or .NET in a way.


Jul 3, 2013
The operating system would still write to the SSD as if it was a HDD, correct? So that the pages / flash cells in the storage device itself would be a separate matter from the filesystem's addressing?

If the filesystem and its addressing of blocks and free space became fragmented, then couldn't that increase the number of non-sequential IO requests, thus hampering performance of even an SSD? Even though the SSD would be moving data around to pages/flash cells in an optimized way, the file system itself would see the logical addressing as being fragmented, and thus issue more IO requests to get the data, instead of treating it as a single sequential access?