Is A SATA 3Gb/s Platform Still Worth Upgrading With An SSD?

Real-World Benchmarks: Five Applications

Another real-world benchmark ends with the 840 Pro performing practically the same connected to SATA 6 Gb/s and 3 Gb/s ports. The difference in completion times is a scant 1.6 seconds. If you're sitting in front of both test runs, it's impossible to tell one from the other.