[R] Bug Report: R for Windows installer fails to enable Intel MKL on modern hardware

[Uwe Ligges]

On 04.08.2025 19:29, mo. sadik khan wrote:
> Dear R Core Development Team,
> 
> I am writing to report a potential issue with the standard R installer for
> Windows. On modern, high-performance hardware, the installer does not
> appear to be automatically enabling the Intel Math Kernel Library (MKL) as
> expected, defaulting instead to the standard, single-threaded BLAS/LAPACK
> libraries.

Yes. Whch documentation tells you it would do so automatically?

Best,
Uwe Ligges



> 
> Here are the details of my system and the steps to reproduce the issue:
> 
> *1. System Information*
> 
>     -
> 
>     *Hardware:* Lenovo Legion Pro 5 Laptop
>     -
> 
>     *Operating System:* Windows 11 x64 (build 26100)
>     -
> 
>     *R Version:* R version 4.5.1 (2025-06-13 ucrt)
>     -
> 
>     *sessionInfo() Output:*
> 
>     R version 4.5.1 (2025-06-13 ucrt)
>     Platform: x86_64-w64-mingw32/x64
>     Running under: Windows 11 x64 (build 26100)
> 
>     Matrix products: default
>       LAPACK version 3.12.1
> 
>     locale:
>     [1] LC_COLLATE=English_United States.utf8
>     [2] LC_CTYPE=English_United States.utf8
>     [3] LC_MONETARY=English_United States.utf8
>     [4] LC_NUMERIC=C
>     [5] LC_TIME=English_United States.utf8
> 
> 
> *2. Steps to Reproduce*
> 
>     1.
> 
>     Performed a clean uninstall of any previous R versions.
>     2.
> 
>     Downloaded the latest R installer from the official CRAN mirror:
>     https://cran.r-project.org/bin/windows/base/.
>     3.
> 
>     Ran the installer using the standard, default settings.
>     4.
> 
>     Opened R and ran the sessionInfo() command to check the linked math
>     libraries.
> 
> *3. Expected Result* I expected the sessionInfo() output to show a
> reference to mkl_rt.dll in the LAPACK line, confirming that the
> high-performance, multi-threaded MKL was active.
> 
> *4. Actual Result* The sessionInfo() output shows Matrix products: default
> and LAPACK version 3.12.1, with no mention of MKL. This indicates that the
> standard, slower libraries were installed. This significantly impacts
> performance for computationally intensive tasks like PCA on large matrices.
> 
> Thank you for your incredible work on R. I hope this report is helpful in
> improving the installation experience on Windows. Please let me know if any
> further information or testing would be useful.
> 
> Sincerely,
> 
> [Your Name]
> 
> 	[[alternative HTML version deleted]]
> 
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