RC can be deterministic in terms of when a destructor gets called. GC languages usually don't support destructors for that reason.

But RC GC is not deterministic, though. All you know is that it will be called when some reference is cleared. You don't know which and when, and you don't know how much work it will do. With modern tracing GCs, though, there are no more pauses, and mostly a constant and small CPU tax, done in the background.

The only significant cost tracing has these days is in memory footprint.

> The only significant cost tracing has these days is in memory footprint.

And that's not insignificant. The top-of-the-line Pixel 6 Pro has twice as much RAM as the top-of-the-line iPhone 13 Pro. Maybe the Android camp is just more eager to play the specs game, but I've long speculated that iOS simply needs less RAM because of its refusal to use tracing GC.

Windows Phones of the Lumia series had historically less RAM than equally priced Android models and the performance with .NET Native was much better.

I used all my models until their hardware died.

How can there be degrees of determinism?

Determinism in programming doesn't just mean "X was caused by Y" (e.g. determinism as a stand-in for the causual chain).

It mostly means "I can know (as in "determine") how much time, or instructions, or calls, or memory an operation will take".

And this knowledge can come in degrees (be more or less fuzzy).

I can tell you I'll come fix your plumbing between 10:00 and 14:00, and it will take between 30 minutes and two hours, or that I'll make a delivery at 9:45.