The AJA System Test and DiskTester benchmarks show that the Samsung 840 Pro SSD performs a bit better in the MacBook Pro with TRIM enabled than without it. However, the performance difference is small. Just remember, turning on TRIM isn't just about speed; it's also intended to help reduce write amplification, bolstering endurance.
According to DiskTester, the Samsung SSD in its brand-new state has a sequential read speed (4 KB blocks) of 51.1 MB/s without TRIM, which goes up to 51.5 MB/s with the feature enabled. The results from AJA System Test and the other passes are similar. Conversely, the results also show that the SSD’s performance does profit more from TRIM in a well-used state. This effect is the most pronounced in AJA System Test’s sequential read benchmark, where the data transfer rate increases from 466.7 MB/s to 512.1 MB/s when TRIM is enabled.
AJA System Test