Well it's a fairly standard tower case with 3 spare 5.25 bays and 3 spare 3.5 bays. Also, it's a mini ATX board with nothing else intalled apart from the raid controller, so there is loads of space inside. I have seen things like ICyboxes, but they are going for near $140 here in the UK. I'm trying to think of DIY ways to mount extra drives. One thing I just remembered is I have sets of runners that seem to be meant for hard drives. Just looking at them now thinking about how I could bolt them onto the case... hmmmm