How much more efficient is applying DSP directly from code versus sending parameters?

Wondering what are some steps the program would be able to skip, and if it is worth doing for frequently updated parameters with relatively simple dsp chain?

Thanks in advance!

I am not quite sure what you are asking. Are you asking whether it is more efficient to use Sends / Returns and setup your DSP chain inside FMOD Studio, or to use System::createDSP, System::createChannelGroup etc to setup the same effects chain in code?
Internally a DSP effect is the same thing, whether created by user code or created inside FMOD Studio, so the performance ought to be the same. Hopefully that answers your question, if not then can you please rephrase your question?

Hi Jeff, thanks for the info! Like say if I want to make a fighting game’s combo counter to control a simple low-pass filter. Would it be more efficient to use System::createDSP and System::creteChannelGroup directly in code comparing to make a parameter in FMOD studio called “ComboCounter” and send the combo counter variable to FMOD studio using this parameter, and then apply the effect.

Under the hood it is still the same dsp being used so there would be no inherent performance difference. You would have more fine-grained control over your resources if you create the DSP in code, and as a result you could implement more optimal usage of the DSP. Adding the DSP in Studio however is simpler and will likely be sufficient for your use case. I would suggest starting with that, and if you find you are having performance issues later on then you can optimize your DSP usage in code.