It runs more than twice as slowly using 8 core than using a single core in inverting large matrix. Tested on 8 core Windows XP 64 machine.
> n = 1000 > n.simu = 100 > func1 = function() + { + x = rnorm(n*n) + dim(x)=c(n,n) + y = solve(x) + } > > setMKLthreads(1) > system.time(for(i in 1:n.simu) func1()) user system elapsed 69.48 2.42 71.91 > > setMKLthreads(8) > system.time(for(i in 1:n.simu) func1()) user system elapsed 179.06 17.90 41.70 Jason Liao [[alternative HTML version deleted]] ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.