Also, Azul Systems solved that issue - the proprietary C4 GC has no pauses, and the heap can be huge, like hundreds of GB. If that tech would become common place, maybe this discussion would be obsolete. But I think C4 requires kernel support, and the first attempt to get a patch accepted didn't go well.
To clarify, Azul's Zing does have pauses, but they optimized the crap out of them (the pauses are more time-to-safepoint rather than GC pauses). GC time wrt application stopped time is constant regardless of heap size.
Azul also sacrifices throughput over the HotSpot GC to achieve very low pause times—the overhead of a GC is not just in its pause times! There's no free lunch.
