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.
The 500GB SL308 shows pretty strong 4K performance at deeper queue depths for both reads and writes. The 4K write performance at shallower depths is also pretty good. Not so strong is the 4K read performance at a shallow queue depth.