Disadvantage of RAID 1
Two hard disks can be counted just as one. This type of RAID function is generally executed by the system software, i.e. the operating system, and hence gets loaded with this work. This results in a decrease in the performance of your operating system and hence the overall performance of your computer. It is thus a very inefficient scheme for data storage. It must have already been clear from the explanation given above, that the data is broken down into blocks and stored in RAID arrays. In RAID level 1, the RAID arrays have a constriction depending on the size of the hard disk.
With the RAID 0 vs RAID 1 comparison given above, you must have already decided on which storage scheme is the best for you. So, if you are looking for high performance and are not too worried about the data backup, RAID 0 is your right choice. But, if you are dealing with crucial data, then ofcourse you need to choose the RAID 1 storage scheme.