Is VivaGraphJS still the fastest?

The readme links to [this video](https://www.youtube.com/watch?v=Ax7KSQZ0_hk) as proof of speed.

But @anvaka I notice you have [a comment](https://www.youtube.com/watch?v=Ax7KSQZ0_hk&lc=z12yyzw40umvgtb2u23zilbavoawff0es.1474484025491153) in the video saying that the new d3-force may be faster:
> Here is the code: https://github.com/anvaka/graph-drawing-libraries/blob/master/src/src/scripts/examples/mbostock_d3/02.perf/index.html - it is very old, and uses svg. I think `d3-force` module from v4 of d3 is much faster now, and beats vivagraph at convergence speed with specific parameters. I'm going to update this video when I find time for it...

What is the current state of truth for relative force-layout algorithm speeds?

Start with the README's linked performance video and the referenced graph-drawing-libraries d3 example. Establish a current, reproducible comparison between VivaGraphJS and d3-force, including the parameters and convergence measure used. Done means the relative-speed claim is current and the README or linked evidence reflects the result.

Written by the indexing model from the issue text.