Snow Parallel R: makeCluster with more nodes than available

Hi all,
	I would like to know what would happen if using snow I create a cluster
of size 50, for example using makeCluster(50,type='SOCK') on a machine
with 2 Cores and run a function. Does snow run 25 and 25 functions on
each of my 2 "real" processors or it just run 50 functions in one
processor ?

Thanks.