Right, scanning large heaps means someone has to pay along the way. The Go GC pays with lowered throughput much like the adapted HotSpot VM is showing. The 10ms

Right, scanning large heaps means someone has to pay along the way. The Go GC pays with lowered throughput much like the adapted HotSpot VM is showing. The 10ms pause times for go were reported for a 250 gigabyte heap, however, and that is pretty amazing. But the lowered throughput has to be present as you are scanning the heap and you have enabled the write barrier to make the concurrent scanning work its invariants. In fact, the newest versions will make aggresively allocating goroutines run slower by using some of their timeslot when they request data do run the mark phase.