FireWire bandwidth is shared between audio interface I/O streams, UAD plug-ins used within the DAW, and external FireWire hard drives. Available bandwidth also depends on the session sample rate; the higher the sample rate, the more bandwidth is consumed. FireWire bandwidth is displayed in the “FBW” meter in the UAD Meter & Control Panel application:
UAD Bandwidth Allocation
The UAD Bandwidth Allocation setting reserves FireWire bandwidth for UAD plug-ins used within a DAW. The default value (65%) allows audio interfaces to run at higher sample rates (88.2 – 192 kHz).
Important: If using sample rates of 44.1 kHz or 48 kHz, we recommend increasing the UAD Bandwidth Allocation setting to allow more UAD plug-ins to run within the DAW. See the table below for recommended values.
Recommended Maximum UAD Bandwidth Allocation Values
|Sample Rate (kHz):||44.1, 48||88.2, 96||176.4, 192|
|Without external FireWire hard drive:||75%||55%||40%|
|With external FireWire hard drive:||50%||30%||20%|
|I/O buffer setting for best playback results:||512||1024||2048|
To change the UAD Bandwidth Allocation setting:
- Quit all DAW software (UAD hosts must be quit to change this setting).
- Open the UAD Meter & Control Panel application.
(Mac) The application can be accessed under the blue UA diamond icon in the OS X Menu Bar at upper right of screen, or click its icon in the Dock.
(Win) Select the application from: Start Menu>All Programs>UAD Powered Plug-Ins>UAD Meter & Control Panel.
- Open the “FireWire” panel within the UAD Meter & Control Panel application. Access the FireWire panel by clicking the menu button in the UAD Meter window and selecting “FireWire...” from the drop menu, or type Command+F (Mac) or Control+F (Win) as a shortcut.
- Change the UAD Bandwidth Allocation setting (shown below) by clicking the up or down arrows, or click+hold the value for a drop menu.
UAD Bandwidth Allocation Notes:
- Important: If switching to a higher sample rate, set the UAD Bandwidth Allocation BEFORE opening a session.
- To run more UAD plug-ins within a DAW, use USB, eSATA, or internal hard drives for audio session files instead of FireWire drives.
- UAD-2 Satellite has intelligent FireWire bus monitoring. If audio playback is compromised, a “FireWire Interrupt Detected” dialog appears. If that occurs, decrease the UAD Bandwidth Allocation setting for reliable playback.
- UAD Bandwidth Allocation values in the table above are recommended as starting points for FireWire bandwidth tuning. Depending on external FireWire hard drive usage (e.g., how many audio tracks are being streamed), lower values may be needed for increased FireWire hard drive loads, or higher values can be used for increased UAD plug-in counts when FireWire hard drive usage is lower.
- (Mac) FireWire performance is better on some systems versus others due to the FireWire controller chips they contain. In general, newer Mac Pro, iMac, and Mac mini systems contain a superior FireWire controller chip and will deliver better FireWire performance than MacBook Pro systems. There is no simple method to determine which controller is used.
FireWire Bus Notes
FireWire Bus Power
- The included power supply is required for UAD-2 Satellite operation. UAD-2 Satellite cannot be bus powered.
- UAD-2 Satellite does not supply bus power from its FireWire ports to other devices.
- When using a FireWire device that requires bus power, connect that device directly to a FireWire port that supplies bus power, such as the host computer itself, or an externally powered FireWire repeater that is specifically designed to supply bus power.
Combining UAD-2 Satellite FireWire with other FireWire devices
- For optimum performance, UAD-2 Satellite FireWire should be powered on after all other FireWire devices on the bus are powered on, but before the computer is started.
- See the Apollo FireWire Multi-Unit Cascading article for additional information about combining UAD FireWire devices.
Mac Pro FireWire Ports
- Mac Pro systems have FireWire ports on the front and rear of the computer. Connect UAD-2 Satellite FireWire to a FireWire port on the rear of the Mac Pro. The front panel FireWire port is unsupported.
FireWire Bus Tuning
- To maximize FireWire bus performance, the UAD Bandwidth Allocation may need to be adjusted. See the FireWire Bandwidth info at the top of this article for more information.