Partitioning RAID "0" configured hard drives.

when the hdds are configured as a raid 0 array on a raid controller, they are seen by windows as one large hdd (the sum of 2 hdds capacity in this case), and functions as a single hdd then too (you cant choose to use one instead of the other for anything then, when they are in raid), the OS will assign C: to the raid 0 array by default, if its installed on the array

you can repartition the array into sections, just as you would a single hdd, but there would be no real performance gain to doing so (the fastest part of the array is going to be at the beginning of the array, with the slowest at the end, just like with a normal hdd)... performance boost from having raid 0 can range anywhere from 0% to ~30% or so, depending greatly on the use you have in mind, and how much 'disk thrashing' youre intending to do... lots of heavy, random, and continual disk accessing... or just browsing online and checking emails and such... or somewhere inbetween even

you should always have backups of all your data, whether youre using raid 0 or not, just incase one of the hdds in the array does fail (which will then corrupt the whole array, making the data on the array unusable then), chance of failure is about as likely as with just a single hdd, but its always worthwhile to have a few backups regardless