When I look at the PS for my D-Ling 7 port it's claims to be 2.5 amps. That's why they run 5 miners. The Rosewill 520 10 port well run 8 miners. I'm working on converting a atx psu for a 30+ amp 5 volt supply.
you put to much through you could fry the hub...
No, not at all. The amount of available current has nothing to do with it. A hub well only take the amount of current the asic's require. My 10 port Rosewill hubs run 10 miners, powered by the 5v rail of a atx psu, rated at +5v/36Amp. I've seen some cheap import hubs that can't supply 0.5 amps per port because of a cheap surface mount fuse that blows, 10 ports needs a minimum of a 5 amp fuse yet some cheap 10 port hubs have 3-4 amp fuses.
There's a thread someplace that shows how to change these surface mount fuses, fairly simple but you need good soldering skills.