First you cant do a raid with a sata and a ssd drive. Raid work with 2 hard drives of same type and size. Two ssd both at 90 gig would support riad or two sata hard drives at 500 gigs each would do a raid.
The mode of the device includes a set of commands that it will recognize. "TRIM" is a brand new command that's been added to the SATA command set but not the IDE set, so my understanding is that devices running in IDE mode don't support it.
Now the kicker is if you raid 2 ssd drives the trim command is disabled. You might be able to run it manually but i havernt looked into that but i will.
FROM ANOTHER FORUM
The general rule of thumb is solid state drives in a Raid array do not support the Windows TRIM function. Instead, the drives rely on what is commonly referred to as "garbage collection". Garbage collection works very well.
There is one exception that I am aware of but it is more of a workaround. Intel has been working on the problem and might have a solution. There are rumors that TRIM support for Intel ssd's in Raid arrays will be included in the new models that will be introduced later this year. No confirmation yet.
I hope this information helps. some say that intels ssd toolbox might suppport trim in a raid but i cant find a clear answer and dont want to give you the wrong info.
I will say a ssd in achi mode is fast that is what i use and i have 3 spare 500 gig platter drives for backup and i just run windows and a few small programs on my ssd it is a 90 gig with 86 gig useable and i have43.3 gig free i transfered all games and big program i dont use alot to a platter drive along with temp files and so on.
http://www.ocztechnologyforum.com/forum/showthread.php?63273-*-Windows-7-Ultimate-Tweaks-Utilities-*&p=442151&viewfull=1
that is a good ssd drive info page for windows 7