Tuesday, August 13, 2013

TRIM support on SSD and how to check if its working correctly.

Unlike normal rotating hard disk drives (HDDs), the SSD drive cannot overwrite existing data. This means that you first have to delete the old data before writing new one. This slow down the performance because the write process first has to delete the "marked up for deletion" data to make up the free space.

To solve this problem, SSD manufacturers and OS has added a new command support called "TRIM" which actually keeps deleting the marked up data. 

Verify the following things to check whether TRIM is working properly.

1. Check if TRIM is enabled from OS Side.
 On Win7/Win8 system run the below command 
"fsutil behavior query DisableDeleteNotify"
if the results if 0 it means TRIM is enabled from OS side and it will send the notification to SSD firmware when a new data is marked for deleted. 

2. Check whether your SSD supports the TRIM
There are couple of ways to check this. The easiest way I found is by using the free crysteldiskinfo tool - http://crystalmark.info/software/CrystalDiskInfo/index-e.html
         Run this and under feature look for TRIM and it’s not grayed out.

3. Use the trim check tool:

 TRIMcheck is a free utility and authored by Vladimir Panteleev from Moldova and is a current GIThub project.

 TRIMcheck will actually check and verify whether TRIM works or not.  This program has no GUI, it runs in a command prompt window.  You must copy it on the SSD that you are testing and run it twice, waiting at least 30 seconds to a minute between runs in order to ensure accurate results.  When executed for the first time it will write on specific locations on the SSD.  It will then delete the written data and exit. When you run it a second time a minute later, it will try to read the exact same locations. When TRIM works you’ll get zeroes on the sectors it wrote, plus a notification that TRIM works.  If the data is still there, you’ll be notified that TRIM is not working.  

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