A RAID10 is a RAID0 volume composed of 2 RAID1 volumes. So you will need 4 at least 4 HDs to built such RAID volume. We do not recommend to use 2 partitions on the same drive to generate 2 virtual HDs, it will strongly affect performance.
If this RAID10 is not the most fancy nor the most performing solution, it is the easiest one to setup in a MacPro to benefit from both performance and secure data storage.
