[R] Performance of graph and igraph package

[William Tu]

Dear R users,

I'm using graph library to create a mesh-like network topology and
implement a load balance routing algorithm. The current implementation
uses graph, RBGL, and Rgraphviz libraries. I have a few attributes on
every edge to represent the network loading and capacity, and I
frequently update these values. However, I found it works so slow and
right now I'm consider rewriting it using C or Python.

Then I found another library, which is "igraph". I made a performance
comparison between "graph" and "igraph" as below. For both graph, I
create two attributes for each edge and set/get the value of all edges
and measure the total elapsed time.
A. using graph package:
108 nodes, 832 edges: 17 sec
140 nodes, 4800 edges: 576 sec

B. using igraph package:
100 nodes, 4950 edges: 4 sec
200 nodes, 19900 edges: 111 sec

igraph is much much faster than graph! Is this reasonable? or I did
something wrong?
ps. I'm using 2 core 3GHz CPU with 2G ram.

Thanks in advance,
William