Ref Trim on U3S6 card. I believe the only real requirement is that the SSD be in AHCI mode (Only mode for Asus card - does not suport raid) and not dependent on Chipset. While it's easy to verify that trim is enable, that does not say that it is working. Here is one discussion on that topic. http://forum.corsair.com/v3/showthread.php?t=86403
Not sure on Intel's rapid Storage driver. I have the card installed and attached the WD Blk sata6 HDD 9Don't really recommend drive) attached. I moved my intel G2 SSD over to it and it booted (during post it recognized it as SATA II device) just fine (it doesn't improve, but did it to check card). After a couple of weeks, moved it back to Intel controller - Paperport 12 did not like (invalid registration).
One "NEW" SSDs they do not rely on trim cmd (altho nice) as they normally have a "garabage Collector" tha substitutes for Trim.
All SSDs require garbage collection, but TRIM informs the drive which sectors are unused and therefore eligible for reuse. A drive that receives TRIM commands will always do a better job of garbage collection than a drive that doesn't (at least if its firmware is half decent...)