Is it standard USB 2.0 or is it USB 3.0 ports?
The protocol doesn't really matter so much but what about the power output per port? If a power supply can provide additional current @ 5v could the hub power say...blue fury miners? They require ~.85 A per port where typical USB 2.0 is only .5 A. But since the power draw is directly from the PSU I don't see why they can't overdraw...
Technally it can matter.
USB 2.0 = 0.5A
USB 3.0 = 0.9A
Also USB 3.0 does NOT work on the Raspberry Pi for thoes that are asking. It requires too much power. Also powering a Raspberry Pi off of a USB 3.0 Hub is not recomended. The Raspberry Pi requires at least 1.0A. It could be powered off of USB 3.0 just not recomened.
However in this matter. Both the Block erupters and the Blue Fury miners are both 0.5A.
https://bitcointalk.org/index.php?topic=297304.0Product Description:
Rated hashrate 2.2 - 2.7 GH/s
Electricity consumption as low as 2.5 watts and 500mA
Large aluminium heatsink will lower the chip up to 20 degrees celsius
Powered by the USB port without any other power source
Firmware is open for more optimization, using highend microcontroller AVR by Atmel
Also the 5v Rail on the psu must supply at least 24.5A to power the usb ports.
https://bitcointalk.org/index.php?topic=49417.msg3415868#msg3415868Update from friedcat: The power supply must supply the current from the 5v rail. This means your PSU must provide at *least* 0.5A @ 5v per erupter you plan to run. Planning at 0.55A per erupter is recommended just to be safe.