I live in a motorhome and frequently without 110 volt power. I want to use a 12 volt power supply to run a 4 Terabyte USB drive as a media server.
already have the 750 slate, but I thought the SMB storage was limited, am I wrong? Was thinking about getting a Beryl if it can handle the 4 Terabyte drive. I would use a powered hub for the USB drive.
I hope someone will answer your specific question. The Beryl is certainly more powerful than the Slate (2 cores, USB3) and the USB port could very well power a portable USB drive. But if you are otherwise happy with the Slate you might think about something like a Pi to be your server. (When they are back in stock).
I think running a router as a server is something of a party trick. It can be done but a router is engineered to do one thing.