We used the the ECS Z97 board with USB 3.0 port as our testbed. We ran CrystalDiskMark 4.1.0 x64 to do a test and we can see that the scores are respectable. For sequential read, it is able to do a 400MB/s way above the 290MB/s promised in the specifications.
The ATTO Disk Benchmark gives a clearer picture of the performance through USB 3.0. The results shows a max transfer rate of Read 393MB/s and Write at 286MB/s.
In SiSoft Sandra Benchmark, it is recognised as an OEM part FORESEE S600M256G. The random write 4K scores 86MB/s while sequential write is 273.64MB/s.
As for WRITE performance, Random 4K write returns 129.2MB/s and sequential write is 439MB/s.