Re: [R-pkg-devel] parallel computing slower than sequential computing

2019-04-30 Thread Wang, Zhu
-Original Message- From: Ivan Krylov Sent: Tuesday, April 30, 2019 10:17 AM To: Wang, Zhu Cc: R-package-devel@r-project.org Subject: Re: [R-pkg-devel] parallel computing slower than sequential computing On Mon, 29 Apr 2019 23:44:42 + "Wang, Zhu" wrote: > sessionInfo(

Re: [R-pkg-devel] parallel computing slower than sequential computing

2019-04-30 Thread Ivan Krylov
On Mon, 29 Apr 2019 23:44:42 + "Wang, Zhu" wrote: > sessionInfo() > R version 3.5.2 (2018-12-20) > Platform: x86_64-pc-linux-gnu (64-bit) > Running under: Ubuntu 18.04.2 LTS Which BLAS implementation do you use? One popular implementation, OpenBLAS, spawns multiple threads to do some

[R-pkg-devel] parallel computing slower than sequential computing

2019-04-29 Thread Wang, Zhu
Hello, I have a package where parallel computing is slower than sequential computing with cross-validation. For instance, please see the following reproducible example with 10 cores and the relevant lines in the corresponding R function. The R package is also attached. I thought parallel