JBOD

Just a bunch of Drives- R/W each HDD independently
FAT format: integrated evenly on both HDD
Sum of dual HDD capacity

RAID 0 

RAID : R/W on both HDD simultaneously
FAT format: integrated evenly on both HDD
Sum of dual HDD capacity

RAID 1

RAID: Mirroring on both HDD simultaneously
FAT format: integrated on both HDD
Half of HDD capacity

RAID / SAFE33

It creates two virtual volumes; one SAFE volume and one BIG volume. It uses a SAFE volume that is mirrored across two hard drives to protect your critical data in the event a hard drive failure. If one drive fails the SAFE volume is retrievable although the BIG volume is not. When you replace the failed drive, the SAFE volume is automatically rebuilt on to the replacement drive.

When using a SATA host connection, you must have a PM (Port Multiplier) aware host adapter when using SAFE33 on the top level node of a cascaded configuration so that ALL volumes can be detected by the host. If your SATA host adaptor is not PM aware, then ONLY the SAFE volume will be detected and the BIG volume will not be accessible. No such limitation exists when using a USB host connection.

The size of the SAFE volume will be one-third of the size of one hard drive (if they are equal) or one-third of the size of the smaller (if they are not equal.) The size of the BIG volume will be the combination of all remaining capacities.

RAID / SAFE50

It creates two virtual volumes; one SAFE volume and one BIG volume.

The Function is the same as SAFE 33, only different capacity adjustment for RAI1/BIG.

The size of the SAFE volume will be one-half of the size of one hard drive (if they are equal) or one-half of the size of the smaller (if they are not equal).

The size of the BIG volume will be the combination of all remaining capacities.