Hitting the “Reply” button on HN takes you to a new page with a textbox, taking over 500ms and a complete page reload. On some websites, that amount of latency is acceptable. But that could be instantaneous.
For me this is 45ms to transfer the 2 kB (compressed) of HTML; the whole process takes under 60ms total, which is pretty darn close to "instantaneous" for the "complete page reload."
EDIT: I'm in Texas, so most of this time is probably just round trip time to the west coast.
It's about 120 ms here (wifi off of gigabit fiber, east coast US.) Based on ping time, over 60% of that time is network latency to the west coast. Actual "processing" would be in the 50 ms range which is super fast.
It may be <100ms, but that completely misses my point. My point is that it could be <1ms, and no reload, if the Reply box was added in JavaScript to the previous page.
