Re: [R] Assigning cores

2020-09-03 Thread Peter Langfelder
The big question is whether each worker or thread uses parallel processing itself, or whether it uses resources like cache in which case 20 threads fighting over the cache would slow you down substantially. If your simulations use operations implemented in BLAS or LAPACK, be aware that some R insta

Re: [R] Assigning cores

2020-09-03 Thread Rasmus Liland
On 2020-09-03 13:44 -0400, Leslie Rutkowski wrote: > Hi all, > > I'm working on a large simulation and > I'm using the doParallel package to > parallelize my work. I have 20 cores > on my machine and would like to > preserve some for day-to-day > activities - word processing, sending > email

Re: [R] Assigning cores

2020-09-03 Thread Jeff Newmiller
Do you have 20 actual cores or 10 cores/20 threads? detectCores() doesn't usually know the difference but the CPU may be too busy accessing memory to let that last thread get any useful work done. I often find that allocating real cores is more practical than thinking in terms of thread so try a

Re: [R] Assigning cores

2020-09-03 Thread Tom Woolman
Hi Leslie and all. You may want to investigate using SparklyR on a cloud environment like AWS, where you have more packages that are designed to work on cluster computing environments and you have more control over those types of parallel operations. V/r, Tom W. Quoting Leslie Rutkows

[R] Assigning cores

2020-09-03 Thread Leslie Rutkowski
Hi all, I'm working on a large simulation and I'm using the doParallel package to parallelize my work. I have 20 cores on my machine and would like to preserve some for day-to-day activities - word processing, sending emails, etc. I started by saving 1 core and it was clear that *everything* was