library(snowfall)

bigProcess <- function( x ) {
	mean( replicate ( 10^6 , max( rnorm( 100 , x ) ) ) )
	}

#run the function twice in parallel
start <- Sys.time()
sfInit(cpus=2,type='SOCK',parallel=TRUE)
sfSapply( c(1,5) , bigProcess )
Sys.time() - start

#faster than running it twice sequentially
start <- Sys.time()
bigProcess( 1 )
bigProcess( 5 )
Sys.time() - start