The vast majority of such "benchmarks" are measuring any one of several different kinds of transfer rates. Most of the tests are flawed and don't tell you very much. Your Nvidia test looks to be pretty close to what's expected on a fully installed and operating system with a drive that's partly filled.
The best "real-world" measurement of transfer rates is the ATTO disc benchmark.
It's the Raptor access times that make is feel fast, not the transfer rate.