From apt-cache show libatlas3gf-base

ATLAS is an approach for the automatic generation and optimization of
numerical software. Currently ATLAS supplies optimized versions for the
complete set of linear algebra kernels known as the Basic Linear Algebra
Subroutines (BLAS), and a subset of the linear algebra routines in the
LAPACK library.

The libraries in this package are built without any processor extension
instructions, and should run on all processors of this general
architecture, albeit less than optimally.

Before version 3.8.3-25, optimized binary packages were provided.
However, due to the fact that most Atlas optimisation are done at build time,
it has been decided to remove them and give priority to locally built packages.

For more information on how to rebuild locally atlas, see the section:

There's a Debian HOWTO compile atlas with sse2:

zless /usr/share/doc/libatlas3gf-base/README.Debian.gz

To install the optimized package on the virtual box, follow the commands below:

sudo apt-get update
sudo apt-get build-dep libatlas3gf-base
apt-get source libatlas3gf-base
cd atlas-3.8.3/
fakeroot debian/rules custom
sudo dpkg -i ../libatlas3gf-base_*.deb