title: Betweenness centrality for relatively large scale data
body: <p>Using R,I try to calculate Betweenness centrality for about 1 million nodes and more than 20 million edges. To do so I have a pretty decent machine with 128GB ram and 4*2.40GHz CPU and a 64bit windows.
  Yet, using betweeness() of Igraph takes ages. I am wondering is there any quick solution? would it be faster, if I use Gephi?!</p>