High power bus-powered drives are supported only by the Allegro Pro USB 3.0 PCIe (USB3-PRO-4PM-E), Allegro USB 3.0 4-Port PCIe (USB3-4PM-E), and Tango 3.0 PCIe (FW8USB3A-E) cards, but not the discontinued USB 3.0 PCIe cards (USB3-E or USB3M-E), the initial version of the Tango 3.0 PCIe card (FWUSB3-E), nor any USB 2.0 cards.
If you are still having trouble, this may be a problem due to a voltage drop in the USB cable. Use the following guide to select the correct cable for your application.
In general, these cables should work with SSDs or optical drives drawing up to 2A of current:
Type........Power-Carrying Wires....Cable Outside Diameter....Maximum Cable Length
USB 2.0..........28 AWG...............................3.8mm...........................0.15m (0.5 ft)
USB 2.0..........24 AWG...............................4.7mm...........................0.3m ( 1 ft)
USB 2.0..........20 AWG...............................5.0mm..............................1m ( 3 ft)
USB 3.0..........22 AWG...............................6.0mm..............................1m ( 3 ft)
Generally, the gauge of the power-carrying wires can be inferred from the cable outside diameter.
