Effects consume CPU resources. In general, CPU usage increases with the number of Effect instances that play at the same time, although there are several additional considerations:
Number of channels. CPU usage increases with the number of audio channels, and the number of channels varies with the audio bus. For example, three instances of an Effect on a mono sound (three channels) use fewer CPU resources than a single instance of an Effect on a 7.1 bus (eight channels).
In addition, certain Effects such as Object Processors, are only instantiated once per bus instance. For more information on Effects, Audio Objects, and buses, refer to Using Effects with Audio Objects.
Type of Effect. Different types of Effect use different amounts of CPU. Reverb Effects are a special case, because although most other Effects cause a linear increase in CPU usage as the number per channel increases, reverb Effects have a flatter rate of increase. Within the reverb Effect category, different types of reverb use different amounts of CPU: Matrix Reverb uses less CPU than RoomVerb, for example, although it has fewer options. Other Effects, such as Compressor or Parametric EQ, use less CPU than reverbs.
Effect rendering. One way to reduce Effect CPU consumption is to render Effects so that they are part of the WEM files themselves. When Effects are rendered, they are processed before they are packaged in SoundBanks and therefore do not consume runtime processing power. You can identify Effects that are good candidates for rendering through the Integrity Report: select the Optimizations option and run the report. For more information about rendering, refer to Rendering Effects.
Bypassing Effects. If certain Effects are only applicable in certain situations, you can selectively bypass them. For example, if you have a distortion Effect that only occurs during certain player states in a game, you can use an RTPC to apply a Bypass Effect linked to a Game Parameter that monitors player states.