I have no idea which one is faster, I haven’t done any tests myself so don’t take my word for it. But according to a Cfx element “an equivalent busy-loop in JavaScript is about 15% slower”.
There’s also some old “benchmark” tests provided by a community member that has been around for quite some time. They’re however over one years old so I’m not sure how relevant those are. I’m also not sure how it’s been tested but here they are: