And as a general rule (in case anyone else comes across this thread looking for more general information), most devices use 6-pin cables, with the exception of camcorders, which universally use 4. The reason for this is mainly one of space constraints on camcorders (and a bit of historical convention). Officially, non-bus-powered devices can use 4-pin, but most devices use 6-pin connectors anyway, as they usually have more than one port.
Most computers use 6-pin connectors, too, with the exception of some laptops (and some of Sony's desktops, IIRC). Computers with 4-pin connectors can't provide power to devices, which means that bus-powered devices won't work unless there is another way to provide them with power. Most audio interfaces are not bus-powered devices, however, and most of the ones that are come with
a power pack to provide power if your computer doesn't.
Do not use both a 6-pin to 6-pin cable and an external power supply on any device that is capable of being powered by the bus. Ever.