It shouldn't matter very much. I've heard that for small calculations the LabVIEW math primitives are a little faster and for longer calculations the formula node sneaks ahead but since all LabVIEW is compiled before execution it tends to be pretty even. It may also matter whether you are working with big arrays and if your PC has many cores. See here:
Formula nodes: code readability comes at a price - LabVIEW General - LAVA (lavag.org)
The best bet would be to create a simple test similar to what you need to do and then run some benchmarks with primitives vs formula node.
LabVIEW Pro Dev & Measurement Studio Pro (VS Pro) 2019
