ZGC (JVM) now has guaranteed maximum pause times of 500 microseconds, with average pause times of just 50 microseconds: https://malloc.se/blog/zgc-jdk16
Pause time is not the same as cycle time, but it’s what’s important for reactivity.
Sure, but deferring collection requires increasing memory use. Since the OP was discussing microcontrollers, that's generally not desirable because memory is in short supply. A 1ms GC cycle is totally tolerable for most microcontroller applications though.
I was responding to your statement regarding “on desktops and servers”, which I believe doesn’t quite represent the state of the art anymore. I certainly agree that 1 ms is already pretty short.
Pause time is not the same as cycle time, but it’s what’s important for reactivity.