...
By the way, although the vibe.d HTTP implementation naturally adds some
overhead over the raw network I/O, the vibe.d results in that list,
judging by their poor performance on many-core machines, appear to be
affected by GC runs, or possibly some other lock contention, whereas the
basic HTTP request handling should be more or less GC-free. So those
shouldn't be used for comparison.
Last time I checked the main reason why vibed was slower has been because of HTTP parsing. vibe-core with manual http parsing has been the same fast as all other fastest alternatives.