SSD Trim: Knowledge of SSD You Cannot Miss

What is SSD trim, and how do you enable SSD trim support in Windows 10/8/7? Find the answers in this tutorial and learn how to use trim software for SSD drives.


By Lucas / Updated on May 12, 2023

Share this: instagram reddit

Nowadays, SSD drives are becoming more and more popular due to its advantages such as less power usage, faster speed, and higher reliability. However, when it comes to SSD, not everyone knows it clearly especially its terms, taking trim SSD for example. How much do you know about SSD trim?

ssd drives

What is SSD Trim?

In order to know what SSD trim is, first you need to understand how SSD works. SSDs look like traditional hard drives, but they record data in different ways. Typically, SSDs use NADA flash memory to store data and a flash controller to connect the memory with the host computer. For SSDs, data is stored in blocks. Each block consists of more than one file; we compare a block as a notebook and a file as one page of the notebook. For SSDs the data on notebook can be wiped when it is necessary. However, if you delete data on a page it isn’t really deleted, it is marked as deletion. This is because data can be only deleted in blocks. Over time, you find the blank pages are going to run out and you need more blank pages to store new data. But you can’t write directly on the page which you have written and you want to make a deletion. At this time the marked pages will get together as a block and the whole block can be deleted.

When you want to delete data in block, this work depends on garbage collection which is the erase cycle for NADA flash memory. Garbage collection begins to work when a block is full of data including valid and invalid data. The valid data must be wiped to make room for new data, so the flash memory controller copies the valid data of the block to a previously erased block and ignores copying the invalid data of that block. Then the final step is to erase the original whole block, leaving the space for new data to be written.

The easing takes time and it can cause serious delays which relies on how much data you want to delete. Fortunately, trim resolves this problem. Because a trim command allows your operating system to find the marked pages before you need them and erase them clean. In this way, cleaning data in advance saves your time when you need to write data on the page again.

Attention: Garbage collection only available to your SSD, when it is idle. So you should make sure your computer doesn’t go to sleep when it’s idling. Besides, it takes Garbage Collection time to do its work, but when it is idle, your SSD will maintain its high level of performance.

Over-Provisioning (OP)

Before or during garbage collection, the copy of valid data is in 2 or more locations which are called write amplification. In order to store this extra data which isn’t counted by OS, the flash controller needs some spare space. This is called OP, and it plays an important role in every NADA SSD.

Each SSD has the amount of OP. the different amount depends on tradeoffs made between the capacity of total storage and profit in performance and endurance. The less amount of OP is in SSD, the more information users can store. But most of the users don’t know, not stretching OP area too thin makes you have lower write amplification, which converts to a higher performance during writes and longer endurance of the flash memory.

How to Enable Trim Support for Windows 8 and 7

Before you do:

  • Make sure your operating system support TRIM command.

  • Make sure your solid state drive's firmware support TRIM.

At first, check if the trim command has already active in Windows:

1. Open a Command Prompt window (run as administrator) Click on Start button → Click All Programs → Accessories → Command Prompt

2. Input fsutil behavior query DisableDeleteNotify at command prompt and press enter.

Two possible outcomes:

DisableDeleteNotify = 0 : TRIM is already available and working in Windows

DisableDeleteNotify = 1 : TRIM is not available, do as step 3 to enable it

3. In order to enable SSD TRIM support in Windows, input following information at command prompt and press enter:
fsutil behavior set DisableDeleteNotify

Optional: SSD 4K alignment for performance enhancement

Besides SSD trim, another way to improve performance of SSD is 4K alignment. SSD adopts the smallest 4K sector in file system to save data and if the smallest 4K allocation units are not always aligned with the 4K pages in SSD, the performance of SSD could be downgraded. So, this time, I recommend a very impressive utility to help 4K align SSD within only a few steps – AOMEI Partition Assistant Professional.

Free Download Win 10/8.1/8/7/XP
Secure Download

Note: Before enabling 4K alignment, you should first check whether your SSD is 4K aligned.

partition alignment


From the above mentioned, you can clearly know that trim support is important for SSDs to have high performance. So in order to avoid slow writing time and to make you get out of depression, make sure that your SSD contains trim support.

Lucas · Staff Editor
I prefer peaceful and quiet life during vacation,but sometimes I watch football match if my favorite club performs brilliantly in that season. And I love reading, painting and calligraphy, thus I send my friends festival handwriting cards every year.