Best setting for RPi 3B/3B+

Hello,
I just succed running processing and minim on pi3 B, and after lot of sweat, setting AudioInjector sound card (this could be a other topic)…
I run fft from stereo input and full audio buffer reading for generative graphic. Sometime I drop to 10-12fps so I asked myself about the best setting of RPi3 for running exclusively processing scketches.
What about GPU/CPU memory split, running from USB drive, more or less soft overclocking?
Other tips…?

Did anyone have experience? I didn’t find anything about “RPi tunning” for processing…

cheer’s

Are you playing from a wav or aiff file?

live stereo input from this : http://www.audioinjector.net/rpi-hat .
tricky to set up, but now it seems to be stable…