TRIM Performance:
While SSDs offer many benefits, there are some downsides to using flash memory. One of the biggest issues people run into is performance degradation. Over time, an SSD will run out of fresh blocks and will have to write over data the file system has marked as deleted. This procedure is very complicated and can slow an SSD's write speeds considerably.
To fix this problem, most manufacturers have added TRIM support to their SSDs. The TRIM command allows an operating system, such as Windows 10, to tell an SSD which data blocks are no longer in use. Using this information, the drive pro-actively erases these blocks and adds them to the free block pool.
To test the 970 EVO's TRIM and garbage collection functions, I first put the drive in a "dirty" state. I used Iometer to fill the entire drive and then ran a random write test for 30 minutes. This had little impact on the 970 EVO's read speed. However, its average writing speed dropped to 444.6 MB/s.
Samsung 970 EVO - Dirty
To see how well the 970 EVO could recover, I let the computer sit for about 45 minutes and then reran the test. The drive wasn't able to reach the factory fresh performance shown in our earlier tests. However, its average read speed jumped up to 1144.5 MB/s.
Samsung 970 EVO - After TRIM
Lastly, I used Parted Magic to perform a secure erase on the 970 EVO. With the drive wiped clean, it had average read and write speeds of 1846.0 MB/s and 1506.6 MB/s, respectively.
Samsung 970 EVO - Secure Erased
