[Beowulf] Which is better; 4 Mountains or 5 Hills

[amjad ali]

Hi All,

Which one of the following two choices are better (assuming both
clusters have nearly same cost):

1) A 4-node cluster having 8 AMD Opteron of 2.6GHz each and 2GB RAM/node

1) A 5-node cluster having 10 AMD Opteron of 2.2GHz each and 2GB RAM/node

Consider GiGE (max 1000mbps) as the interconnect.
Is there any significant performance difference between the two?

Does the compasison depends on the MPI communication among nodes, for
a given application?

Thanking all in anticipation.
Regards.