I may be wrong, but I think that it can't get through in IDE mode, and requires that the controller be in AHCI mode. You certainly have the right OS and board.
Do you know if you have high activity on that drive? Are you by any chance swapping like crazy to a swapfile on the SSD? My personal choice is to put the swapfile on the SSD and use lots of memory to ensure that swapping doesn't happen, but others disagree.