This is the Monoprice 24-port USB hub. I don't have it in front of me right now, but I think the power adapter for it is 12V at 4A = 48W. The Gridseeds are powered using 12V at 7A = 84W power bricks. Each one powers 8 Gridseeds each, and the Gridseeds run in scrypt only mode. I purchased the 20x Gridseed kit from Zoomhash, 4 of them.