With only three times as much memory, it runs on average 17% slower than
explicit memory management. However, with only twice as much memory,
garbage collection degrades performance by nearly 70%. When physical
memory is scarce, paging causes garbage collection to run an order of
magnitude slower than explicit memory management.
I don't see how this article is helping your point; that's a pretty massive hit. Even worse, this is a GC-style program modified to use explicit malloc/free. Programming with manual memory management encourages a very different style of programming where you try to use malloc/free as little as possible, and you try keep memory for various things in contiguous chunks of memory.
EDIT:
This comment is interesting: http://lambda-the-ultimate.org/node/2552#comment-38915