I am not sure this is the best place for this discussion, but it is here so what the heck.
Any idea what gauge the wires are? I have a 5v30a ps but the AWGis 21.. im being told too thin of a wire =/
I doubt that is correct. 21 AWG according to the table I just looked at will handle 49 amps, but not sure at which voltage...
AWG is used for solid wires, chances are good that the multitude of wires coming out of that PSU over to the ATX connector is NOT solid but stranded, this the AWG measure isn't applicable...
Maybe there are some electricians here who can chime in...
ATX power supplies will typically use 16 or 18 AWG wire. Better ones use 16AWG. It is always stranded. I believe the ATX spec calls for 16. I am not sure what table you are looking at but 21 AWG can't handle 49 amps. More like 5 or 6. You can ignore the "free air" column if there is one and look at the "enclosed" or "bundle" column. 16 AWG is good for 10 or 12 amps. The insulation is what determines the maximum voltage, not the wire size. The wire on a random ATX power supply I just looked at is rated at 300v.
I hope these hubs have an internal DC-DC converter and don't use the 5V rail exclusively. This is unlikely due to cost constraints.
I hear they don't which is mixed blessing. The good news is it lets you push as many amps as the connector / traces will carry by providing a bigger power supply. The better news is it doesn't limit the power consumption the capacity of the DC-DC converter.
The bad news is the ATX connector limits the current to 8 amps per pin with 16 AWG wire (
http://www.molex.com/pdm_docs/ps/PS-45750-001.pdf ) and there are only 5 pins for the 5v rail making the total you can reasonably expect before you risk melting the connector 40 amps. Google "tyan tiger mp melted connector" if you want to read stories about what happens if you push too much.
http://imageshack.us/photo/my-images/179/p10101811pf.jpg/ for those who just want the picture.
The harsh reality is there are few modern ATX power supplies with more than 20 amps on the 5V rail and precious few with 30 or more. There are a few like the antec basiq linked above but you have to check the specifications very carefully.
