@FEAR. For a shorter reply than may last one. Yes this is possible with many OS'es. For windows the easiest method would be to create a dynamic disc (you need XP pro at least) and create a stripe (RAID 0) across the two 'areca arrays' (they will appear as individual drives to the OS) this is no functional difference than the linux mdadm approach above but you have a little less control over how the stripe will happen.