ARTIQ/RTIO-performance-and-optimizations.md

@@ -3,6 +3,7 @@ This page briefly describes various observations, optimizations, and recommendat
 ## General
 
 1. Usage of _kernel invariants_ is highly recommended as it allows the compiler to perform more aggressive optimizations. We observed that its usage did not always improve performance, though it never degraded performance.
+1. RPC calls between the host and the core device (context switches) are expensive and best wall-clock performance is achieved when the number of RPC calls is minimized.
 1. We did not observe a significant difference in performance when using _kernel function arguments_ over kernel invariants.
 1. Object attributes that are modified once or more during kernel execution are updated on the host once after the core device returns.
 1. We observed that the core device performance is very sensitive to changes in the program. Adding minor complexity (e.g. adding one local variable) might already measurable influence RTIO performance.