As the offshore market faces deepwater production challenges, the oil and gas industry is investing in new technologies to bring down the costs in the subsea fields exploitation. A breakthrough technology solution is the development of a subsea centrifugal compressor module installed on the seabed, transporting the wellstream to a central platform or directly to shore. They typical application of the module is gas boosting, but it can also be used in the reinjection service. The subsea module concept is made of a package, a compression train (centrifugal compressor, gearbox, electric motor), and a separator as an option. Due to the particular installation site, reliability is an essential requirement to guarantee the module operation. In order to validate this innovative design solution and minimize any risks in the field on future units, thermodynamic and mechanical performances of the machine must be performed over the entire operating range in the test facilities.