2 X 250 GB = RAID 0 stripe with no redundancy. There is no recovery and it's not safe to put mission crit data on the RAID because if one drive fails you lose everything. I run a RAID 0 on my main box, the speed is un-matched and you will show as 500 GB or 465 GB rather. Just remember not save any data on the RAID 0. Good Luck Mate.