[JB_Dev]

It looks like most of the languages are doing the same thing w.r.t using a 'List'-style implementation that re-sizes/copies it's internal buffer when it runs out of space. One thing I wonder though is whether the managed languages pay a bigger penalty on the memory usage than the unmanaged languages due to this.

In the unmanaged languages, those intermediate buffers should be freed immediately during the re-size operation.

But in the managed languages, they might stick around until the next GC. So the peak memory would be higher.

In this example the runtime overhead is going to represent more of the memory usage anyway but it quickly isn't negligible. E.g. a list of size 1M is going to be ~8MB (64 bit addresses). So even if the array is re-sized from 1->2->4->8->...->~500K, the end result is not going to be worse than 2X the size.