Off the top of my head, I would suggest the Phoronix Test Suite
tldr: GPL OS X, Windows, Linux, Free BSD, Solaris, etc. everything you need
The Phoronix Test Suite is the most comprehensive testing and
benchmarking platform available that provides an extensible framework
for which new tests can be easily added. The software is designed to
effectively carry out both qualitative and quantitative benchmarks in
a clean, reproducible, and easy-to-use manner.
The Phoronix Test Suite is based upon the extensive testing and
internal tools developed by Phoronix.com since 2004 along with support
from leading tier-one computer hardware and software vendors. This
software is open-source and licensed under the GNU GPL.
Originally developed for automated Linux testing, support to the
Phoronix Test Suite has since been added for Apple OS X, Microsoft
Windows, BSD, and Solaris operating systems, among other POSIX
compliant platforms such as GNU Hurd. The Phoronix Test Suite consists
of a lightweight processing core (pts-core) with each benchmark
consisting of an XML-based profile and related resource scripts. The
process from the benchmark installation, to the actual benchmarking,
to the parsing of important hardware and software components is
heavily automated and completely repeatable, asking users only for
confirmation of actions.
Also, from their Features page,
Through another Phoronix Test Suite module it is possible to log in real-time various system sensors like the CPU temperature, the battery power consumption, disk read/write speeds, and numerous other sensors.