A hardware limitation on the snap 4100 and dell 705n prevents these devices from being able to address hard drive sizes larger than 128gb. Lots of people who are interested in NAS 'accidentally' purchase these models thinking they can swap out the drives with cheap high capacity drives (plugging in a 300gb drive, for instance, will show up as a 128gb drive and only allow the use of those 128gb). This hardware drive-size limitation, to my knowledge, is ONLY on these two models -- verify the max drive capacity before purchasing other models. The Snap operating system can be loaded on the Dell without problem. These units have a single 10/100 Ethernet network connection. There are no pci slots inside these units to allow for additional connectivity.