Blas version on MacOS


#1

Does anyone knows if julia is using the optimized Blas library provided by MacOS, which is linked by using the accelerate framework.

A call to versioninfo() tells me that libopenblas is used, which is probably not the most efficient one.

Does anyone knows more about this?


#2

Not by default, it’s using OpenBLAS. In the README, it tells us how to build using the Apple BLAS library:

“If you see build failures in OpenBLAS or if you prefer to experiment, you can use the Apple provided BLAS in vecLib by building with USE_SYSTEM_BLAS=1. Julia does not use the Apple provided LAPACK, as it is too old.”

I’ve never tried it. It would be nice to know how they compare. Note that the latest alpha is shipping with OpenBLAS 3.0, which supposedly fixes some performance issues on the mac, or so I’ve heard.


#3

I use macs system BLAS. It’s as much as 2x faster, depending on the task, so definitely worth compiling for.