[igraph] memory usage

[Yulia Matveyeva]

Dear igraph community,

 I have recently been searching for information on how much memory is needed to 
store an igraph object.
 During this search I have found two contradictory posts:
 one (from Tamás Nepusz) claiming that igraph allocates 16 bytes per edge + 8 
bytes per vertex,
and another one (from Gabor Czardi) (it was actually a presentation) saying 
that it allocates twice as much: 
32 bytes per edge + 16 bytes per vertex.

 So I would greatly appreciate if someone could tell me how much memory is 
being used in the current implementation . Or does it somehow depend on the OS 
or the hardware ?

 Since I am looking forward to be able to work with really huge graphs (about a 
milliard edges), the answer to this question is really crucial for me.

 Thank you very much in advance for your time.

-- 
Sincerely yours,
Yulia Matveyeva,
Department of Statistical Modelling,
Faculty of Mathematics and Mechanics,
St Petersburg State University, Russia