It's still deterministic even if the results appear not to be. If you have memory, CPU cache, CPU registers in the same state, you will get the very same results. You need a source of entropy for the results to be non deterministic.
Actually, clock domain crossing for asynchronous clocks (as is AFAIK typical for granular dynamic frequency scaling, like running CPU cores at individual frequencies instead of all at the same, because it quite softly smoothes over to any new target frequency to prevent glitches) implicitly includes thermal noise in the raw transistors that determine which of the two involved clock edges happened earlier (a decision that eventually ends up truly random when they are at (almost) exactly the same time).
And this is involved in even L3 hit latency.
