[Rd] Optimize R: some confusion with Lapack and OpenBlas/openBlas openmp packages.

[arnaud gaboury]

I run Fedora 22 R package. It is build with  --with-lapack \
--with-blas \  --enable-R-shlib \.

As the machine will act as a server with lots of R data computing, I
try to optimize my R package.

At first, I installed parallel_studio_xe_2016 with a free one year
licence. Then, I build a package for R with Intel MKL and compiler.
This took me lots of time as it was my first .rmp build. I finally
managed to build and run it.

Now, when looking at some blogs about R-RBenchmark.25, I realized that
there is very few speed difference between Intel BLAS and OpenBlas. I
am now wondering if such Intel stuff (with its paid licencing) and the
need to build my own R package is really worth.

Do anyone have some realistic point of view/advice?

Then, in case I gave up with the Intel stuff, I am confused between
the Lapack package and Openblas one. I know first one will provide
liblas.so.3 when second one libopenblas.so. Am i right to say I only
need one blas library and the openBlas one is the one to get? Can I
use instead the openmp version of openblas, or shall I installed both?
here again, I am a litle confused.
As for the liblapack.so.3, I will get it from the Fedora lapack package.

last, what is the correct way to tell R to use these shared libraries,
after R has been built?

Thank you for advices and help.

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