AS SSD is a great free tool designed just for benching Solid State Drives. It performs an array of sequential read and write tests, as well as random read and write tests with sequential access times over a portion of the drive. AS SSD includes a sub suite of benchmarks with various file pattern algorithms but this is difficult in trying to judge accurate performance figures.
Although the BX500 won't win any prizes for read performance in the AS SSD benchmark, the write score of 476 is very good for this class of SATA based SSD.