Defraggler and SSDs

As with a standard HDD, over time, the performance of an SSD will deteriorate with use. Defraggler is now able to optimize your SSD using a TRIM function.

Note: The Defrag functions of Defraggler should not be used on solid-state drives due to the fact that they may shorten the lifespan of these drives or even damage them outright, while also having no impact whatsoever on the drive's performance. More information here.

What is the TRIM function?

When you write a file to a new SSD, it will be written directly to the block at full speed. However if you then delete this file, it is not instantly removed. The space it occupies is instead marked by the operating system as “not in use”. When the space is required by the operating system, it will overwrite this space.

However, unlike a standard HDD, it cannot do this in one action. It must first erase all the data before it is able to write the new information to the block. When deleting a file on an SSD, a TRIM command is also sent to wipe the marked block clean. This means that the SSD can now write to a completely blank block.

More information can be found at

For TRIM to work, both the operating system and the Solid State Drive must support the feature, and it must be enabled in the operating system.

You can enable TRIM in the operating system using the following steps:

  1. Click on the Windows Start button (WinLogo.gif)
  2. In the Search box, type: "cmd"
  3. Right-click the Command Prompt result > click Run as Administrator
  4. Type and enter: "fsutil behavior set DisableDeleteNotify 0"

Otherwise unfortunately, older SSDs are not capable of supporting the TRIM function, and TRIM is only supported in Windows 7 and later operating systems. 

Note: You can use our Speccy software found here to determine if your current configuration supports TRIM.

Is TRIM not supported by your SSD, or by your operating system? Fear not, as Defraggler is able to use an alternative method to help improve the write speed performance of your SSD. This is by using a method called, Zero Filling.

What is Zero Fill?

The performance of an SSD is based around the time taken to write to a block. This is at its quickest when the block is blank (zero-filled). If there are no blank blocks left, blocks must be erased to provide space for the new data. This slows down the writing process. If there is no TRIM function available, the SSD cannot erase the blocks in advance.

To prevent this from occurring, Defraggler can overwrite all of the free space on the drive with zeroes so that there's a supply of fresh, 'empty' blocks available to be written to. This can take longer than a TRIM, and puts a little more wear and tear on the drive, but is a viable alternative for configurations that do not support TRIM.