1) Use the Intel Sata III port, NOT the marvel.
2) Set to AHCI, Once windows is installed switch default msahci driver to the latest Intel RST driver (iaSTor).
.. Verify latest Firmware for SSD and latest Bios revision for MB. then
.. Delete all partitions and run Secure erease to clean drive up.
.. Reload windows
NOTE if You keep "reloading Operating system" and Run benchmarks, YOU will get LOW scores. need to do a Secure erease, Then load OS.
Benchmark utility is great to run right after OS instal just to verify it is working. But it is not advisable to run multiple passes with giving SSD time to recover.
For benchmark use AS SSD - YOU will NOT get advertised ATTO specs. But look for a review that shows Benchmark results using AS SSD. It will show which driver is being used and if the Partitions are properly aligned.
ATTO (A HDD benchmark utility) may show GREAT "irrelavent " High performance (Uses Highly compressable data) Scores, But AS SSD (Also not perfect) gives results that are closer to real life.
On Trim, you can check to verify that it is enabled - But there is no verification that it was passed and acted on - Other than do a bunch of deletes then reverify performance.