t is difficult to say as each RAID level has pros and cons.
RAID 0: is excellent for speed but poor for data reliability
RAID 1: offers reliability, but this comes at the cost of speed and occupies double the space
RAID 5: provides reliability and speed and does not require double the space, but you need a minimum of three drives. RAID 6 is similar but requires more drives.
RAID 10(1+0) offers the best of RAID 0's speed and RAID 1's redundancies, but you need more drives to implement it.