I wouldn't be so sure. There is no easy answer. It typically wins in trivial benchmarks, where the total heap size is small. However once you have a big heap of

I wouldn't be so sure. There is no easy answer. It typically wins in trivial benchmarks, where the total heap size is small. However once you have a big heap of other long lived stuff, there is a significant indirect cost caused by scanning the heap, memory barriers and evicting good data from caches. This cost is negligible only if your total heap size is much larger than the live memory set. Also modern manual memory allocators are not as slow as they used to be a few decades ago and they actually allocate in low tens of nanoseconds.