ATLAS is an automatically tuned linear algebra software library providing C and Fortran77 interfaces to a portably efficient BLAS implementation, as well as a few routines from LAPACK.

Optimization occurs at build time. For this reason, the library is built on the machine where it is installed, without resorting to pre-built substitutes.

Before building the library, CPU throttling should be disabled. This can be done in the BIOS, or, on GNU/Linux, with the following command:

# cpupower --governor performance

Failure to do so will result in a library with poor performance.