It supports raid, which means the harddrives inside are set up in some sort of raid config, it says JBOD, raid 0 and raid 1. Hope that answers your question.
You need a special designed file system that support some way to spread files evenly on several independed discs. Neither FAT og NTFS does support this.I just wanted to use it as two independent harddrives. Like JBOD, but if one crashed I don't want to have to go to the extra effort of recovering data from the good drive.
I probably left out that I have two internal drives that are already backups. These two external drives are meant to be duplicates of the backups, but not real-time mirrors as I am more likely to botch the files than the HD failing. So I don't need RAID 1 anywhere.Trust me, you do want some RAID configuration.
If you use RAID in a Mirror configuration you shouldn't notice any speed issues.
Hopefully there should be a RAID controller on the device which handles all the clever stuff.