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 7, 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 960 PRO's TRIM and garbage collection functions, I first put the drive in a "dirty" state. I used Iometer to fill 80% of the drive and then ran a random write test for 30 minutes. Looking at the screenshot below, you can see that the 960 PRO's average read and write speeds dropped to 2456.65 MB/s and 475.83 MB/s, respectively.
Samsung 960 PRO - Dirty
To see how well the 960 PRO could recover, I let the computer sit for about 30 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 write speed climbed up to 1797.74 MB/s.
Samsung 960 PRO - After TRIM
Lastly, I used Samsung's SSD Magician software to perform a secure erase on the 960 PRO. With the drive wiped clean, it had average read and write speeds of 3040.64 MB/s and 1973.73 MB/s, respectively.
Samsung 960 PRO - Secure Erased
