Firewire vs. pcie, Firewire bus power, Bus powering example – Universal Audio UAD POWERED PLUG-INS ver.6.1 User Manual
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UAD Powered Plug-Ins Manual
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Chapter 11: UAD-2 Satellite
FireWire vs.
PCIe
The maximum possible data throughput even at FireWire 800 speeds is only
a fraction of what is possible with PCIe. Therefore, if very high UAD plug-in
counts are required, UAD-2 PCIe cards provide an alternate solution.
FireWire Bus Power
Some FireWire devices can be “bus powered” which means the device de-
rives its operating electricity from the FireWire bus itself without a power sup-
ply of its own. This operating current, when available, is supplied via two con-
ductors in FireWire cables and ports (4-pin FireWire 400 cables and ports
cannot supply bus power).
Although bus powering is part of the FireWire specification, it is an optional
feature. Not all FireWire devices are designed to use it nor are all devices de-
signed to supply it, for a variety of reasons. For example, a device may re-
quire more current than can be supplied by bus power, or a device may be
unable to provide enough current to its FireWire ports.
UAD-2 Satellite cannot be bus powered nor does it supply bus power from its
FireWire ports to other devices. Therefore, when using a FireWire device that
requires bus power, it is important to connect that device directly to a
FireWire port that supplies bus power (such as the computer itself or an exter-
nally powered FireWire repeater that is specifically designed to supply bus
power).
Important:
UAD-2 Satellite cannot be bus powered and it does not supply
bus power from its FireWire ports to other devices.
Bus Powering
Example
illustrates the proper method of connecting bus pow-
ered FireWire devices with UAD-2 Satellite. An externally powered FireWire
repeater or hub that is specifically designed to provide bus power to con-
nected devices must be used in this case.