mclovin, may I suggest on-board DC-DC converter for 12v to 5v? Having that many USB miners might be dangerous. Most ATX power supplies only have 16-24 amps on the 5v rail, which is 32-48 miners, minus whatever the computer is actually using on the 5v rail.
Most modern ATX power supplies are really a large 12v power supply that downconverts the 12v to 5v and 3.3v on an internal daughterboard that usually maxes out around 80-120 watts. I think it would be more prudent to convert that massive source of 12v to 5v instead of relying on the much smaller 5v rail on the ATX PSU.
I had considered a DC-DC converter, but I instead purchased one of these for the stacker:
![](https://ip.bitcointalk.org/?u=https%3A%2F%2Fi.imgur.com%2FW0rft5l.jpg&t=665&c=axOD-8zGMnuJgw)
A 60A @ 5v PSU for $47. We will probably carry these at WTCR soon.
The Stacker 810 supports two power supplies, so I have that added flexibility, and if you have a string of 3 molex's on one wire, that's still only one wire that can carry 5v. So my secondary power supply has two strings on it so that's running two of the 13-port hubs, and the Corsair I'm using as a primary PSU only has one molex string so that isn't enough, I'm using a sata-molex adapter to give power to one of the hubs, but I am still short on being able to power up all the ports just yet. I still have a whole bunch of D-Link hubs so I am using them for some of my USBs until my big 60A PSU arrives then I will be able to power up hopefully 12 of these 13-port hubs. Even that isn't enough power for all 12, but I have two of the 60A PSUs on order, I will get 156 USBs in a Stacker 810 if it's last thing I do!
![Smiley](https://bitcointalk.org/Smileys/default/smiley.gif)
Good read. Let me know how it works out. BTW, 4-pin perephrial plug (most call it molex) spec says 11 amps max per pin or wire, so thats 55 watts or 22 USB miners on that single molex line before you go out of spec and possibly start melting plastic or insulation.
Also, try to keep your eyes peeled for active PFC, and high efficiency, at least 80%. Higher is obviously nicer. I had considered getting a dedicated 5v power supply, or just getting USB hubs that take in 12v and internally convert 12v to 5v so one could power the hubs with a their 12v heavy ATX power supply, but I quickly realized how unprofitable the BE USB's would have been.