This is a caching product sequential throughput is all that relevant. Also this SSD using a HFS file system when the Expresscache software is used so traditional benchmarks would not work. You can check the speed by running IO meter or similar apps to test the overall performance of the machine. Testing the speed of the SSD is not really the way to test a caching system. Overall system performance tests are a better way to go.
If you want to see the speed of the SSD you can delete the partition and format it as a regular drive then run crystal disk mark or ATTO on it to see throughput of the SSD.