The TRIM command is sent by the Windows Operating Systems from Win7 up to the SSDs and is able to clean the cells, which contain finally deleted data, and make them reusable at once.
Problem: It is not easy to verify, if the TRIM command really arrives at its destination, the single SSD or the SSD RAID array. Until now there is no tool available, which is able to detect, if TRIM really is working or not. The mostly used TRIM detection method is to fill up the complete single SSD/RAID-SSDs storage space with data and to look how long it takes until the benchmark results are recovering. Since this method destroys all data and additionally stresses the SSDs, I do not really recommand it for "normal" users.
Here is an easy method, which works fine and does not have any negative impact on the performance and stability of a running single or RAIDed SSD system. The only thing you need is a Hex Editor like HxD.
This is the procedure (credits go to Marc HFR, who has published the method >here<):
- Open any JPG file (should be outside drive C:!) with HxD and copy any unique text code fragment you see on the right side (without any blank space within it).
- Copy the JPG file to the root of drive C:.
- Run HXD as Administrator and hit "Extras" > "Open drive" > "Drive C:".
- Let HxD search for the previously copied file fragment and note the offset value (left side) and the sector digits (right side), where you found the file fragment of the JPG file.
- As colleteral security action let HxD continue the search until you get the message "cannot find ....") (to exclude, that there are more files with the same data on drive C).
- Open the Explorer and delete the JPG file from drive C: and then empty the Recycle Bin.
- Run HxD again as Administrator, hit "Search" > "Go to...." and enter the exact offset value you have noted before. Wait until the tool found the place. On the right side you must see the same sector digits you have noted.
- Scroll a bit down to get the entire sector, where the JPG file was.
- Now you see either the same Hex codes as before (=TRIM doesn't work) or - depending on the SSDs - just 00 00 00 resp. FF FF FF. In the latter case TRIM has cleaned the cells. No Garbage Collection would be able to do that within seconds.
This is how the exactly same hex data section looks, if TRIM is working (freshly deleted data have been zeroed out at once):
By using this method I found out, that Trim was not active within the RAID0 of my Z68 system (first pic), whereas TRIM worked within the same RAID0 array after having replaced the mainboards by a Z77 chipset one (second pic).
If TRIM should work within the RAID, but the "Easy TRIM test" fails, here are some advices:
- Some SSDs need a reboot after the delition of the test file to begin the cleaning procedure.
- Precondition for the TRIM support is the detection of the SSD by the OS. Users, who are working with Win7 or Win8, should run the Windows Experience Index (WEI) at first. Only this way they can be sure, that the SSD will be detected as SSD by the OS.
- After having done the Windows Experience Index Win8 users should run the new Win8 Optimizer (former Defrag Tool), which will send a lot of TRIM commands to the SSD. Some SSDs need a TRIM push to start with the cell cleaning.