[R-sig-hpc] Difference between PSOCK and MPI?

[Marius Hofert]

Dear expeRts,

What are the main differences (advantages/drawbacks) between parallel's makeCluster(,
type="PSOCK") and makeCluster(, type="MPI")? According to
http://cran.r-project.org/web/views/HighPerformanceComputing.html, MPI has
become the 'standard', although the default type of makeCluster() is "PSOCK". Is
"PSOCK" more compatible in that it does not need an installation such as (open)MPI? slower/faster/no difference? 

Cheers,

Marius