[Top][All Lists]

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: Instructions for Installing BLAS and LAPACK library on Octave 5.2.0

From: Ian McCallion
Subject: Re: Instructions for Installing BLAS and LAPACK library on Octave 5.2.0
Date: Tue, 29 Sep 2020 17:54:47 +0100

On Tuesday, 29 September 2020, Nicholas Jankowski <> wrote:
  • Downloading Octave 5.2.0-64 bit executable from the official GNU Octave website( for Win 10
  • Installing the same and checking with the default OPENBLAS library.
  • Assigning the value for the environment variable  OPENBLAS_NUM_THREADS = "the number of processors we need to utilize"

The second step is not necessary. Otherwise yes.


 Do you mean the installing or assigning step?  

My apologies. I was away from my desk any failed to give the question my full attention.

Install ( of course), but the default installation does result in libopenblas.dll being copied to libblass.dll so that "checking with the default OPENBLAS library" is not necessary.

In my default config zip install, OPENBLAS_NUM_THREADS was empty.  I set it to different values from 1-4 since I have a 4 core machine, and didn't notice any real difference running that test routine you posted.  i extended the 1e8 to 2e8 and 1e9 to get meaningful runtimes, but there seemed to be no difference changing the value of that option.  in all cases multiple cores were taxed on execution.  It's a managed machine so I don't have Process Explorer to actually verify the thread count, so maybe other things are happening that I'm not noticing.

I have the same result. I have task manager and whatever the value of  OPENBLAS_NUM_THREADS the execution time is the same and the cpu utilisation peaks at the same level so it would appear the environment variable is being ignored. I will investigate further as my system uses this, succesfully I believe!

Cheers Ian


reply via email to

[Prev in Thread] Current Thread [Next in Thread]