Putting the temp files on the AID might speed it up, but it depends on the physical maximum transfer of the drives involved and RAID usually slows down the drives a bit.  Although I agree about corruption and running Apps on the array.  It's generally not a good idea.  I use my 4 RAID Mirrored drives just to store important data.  I believe there are some good articles about RAID at Tom's Hardware.

Quote -  Hi dagaffer,

As a rule, running  applications on a RAID is avoided because if one of the drives fails or is corrupted, everything on RAID is unrecoverable. 

So, run Carrara on your primary drive. However, if you want to target  your raid for the temporary documents files, you will see a modest increase in performance.

Mark