Batch mode vs no graphic card at all

Hi, I'm about to set up a server machine for networked unity game. Server will run multiple Unity standalone builds in batch mode. However, question is - will Unity be fine about running on a machine with no graphic card at all? Batch mode is supposed to completely turn off the graphic calculations, however what if Unity borrows some processing power from graphic card for standard calculations? (which I don't think is the case, but I'd prefer to be sure.) Does anyone know any good source elaborating on the issue? (I mean, more than few sentences in official Unity documentation). Or maybe anyone has some experience in the matter?