Many options are available to you when you use effects in Wwise. Using certain strategies when implementing effects can give you better-sounding results and save resources. The following are some strategies you might consider when using effects in your projects.
Effects will always use up CPU power, but being aware of this power draw can help you use them more efficiently. In general, if you apply effects at the Master-Mixer level, you will use less CPU. For example, if you apply a Wwise RoomVerb effect on the Master Audio Bus of a game, you will have only one instance processed at runtime. If you applied the Effect at the object level instead, you could have hundreds of instances processed at once.
Rendering effects also allows you to save on CPU, as this will avoid the need to process them in real time. Naturally, you cannot apply RTPCs to rendered effects as the properties of these effects cannot change after they have been rendered.
As far as individual effects go, Delay and Wwise Parametric EQ tend to use very little CPU. The Wwise Compressor, Peak Limiter, and Expander effect use somewhat more. For reverb, you have a choice between the Wwise RoomVerb, which is more resource-intensive but of high quality; and the Wwise Matrix Reverb, which you can adjust to suit your quality and performance needs.
Overall, your best strategy is to test your project using the game profiling tools. In this way, you can observe the CPU usage of effects in real time and make decisions about how effects should be used. For more information about profiling, refer to Understanding the Different Types of Profiling in Wwise.
Applying time-based Effects (such as Wwise Matrix Reverb or Delay) to music objects at the object level is not recommended, as this can interfere with time-based properties and behaviors already assigned to them. Applying the time-based effects at the master-mixer level, that is, to an Audio Bus, avoids this interference.