Numbers imply that Thunderbolt is faster than USB 3.0. But, is there any external hard drive that can really reach this speed?
In this ssd benchmark the fastest SSD (2016) has a write performance of 512MB/s (read performance is a little bit higher, but not significantly)
Wikipedia shows 5GB/s as maximum throughput of an USB 3.0 port.
As you can see, this is a multiple of the maximum of what a current hard disk can support.
To answer your question: There is no external hard disk (at the moment) that would use the higher speed of thunderbolt.
An article from 2 years ago did explicit tests and found out: no difference in speed for thunderbolt vs. USB 3 regarding hard discs.