Question

I am using a Pentium 4 HT machine at office for running R, some of the code requires plyr package, which I usually need to wait for 6-7 minutes for the script to finish running, while I saw my processor is only half utilized.

I have heard of using Multicore package in R for better utilizing the multicore processor, is my case suitable for this?

Thanks!

Answer 1

There is a bunch of packages out there to do multicoring. See doMPI, doSNOW, doMC and doSMP. They are all front ends for other programs that run parallelization (like MPI/OpenMPI, multicore package…). On Windows, I’ve had good experience with doSMP while on Linux doMC looks promising (with some support for windows emerging, but some people have doubts about emulation of “fork”).

That being said, I concur with Vince’s comments about need to write plyr function to use the power of parallel computing. You could write your own function that emulate plyr (or edit plyr) that uses %dopar% (see foreach package as well).

Two “CPU usage history” windows could mean two cores or multi-threading. For instance, I have an i7-920 processor with 4 cores, but I see 8 history windows, because each core is multi-threaded.

Excuse my vocabulary and/or logic, but I would be that fish in Vince’s post when it comes to these sort of things.