Gas-insulated systems (GIS) are established in the electrical industry since the 1960s. Most systems are realized with the insulating gas sulphur hexafluoride (SF6) due to its very good insulating properties. However, SF6 is the strongest known greenhouse gas with a global warming potential of 24’300. The reduction of climate-effective gases such as SF6 is aspired to decelerate the anthropogenic climate change. Therefore, eco-efficient insulating gases have been developed and advanced in the last decades. Typically, partial discharge (PD) measurements are used to identify location and type of possible defects. Minor differences regarding the PD behaviour between eco-efficient gases and SF6 are expected especially due to different discharge phenomena. The objective of this contribution is to analyse different PD measurement methods and devices regarding their sensitivity and assess a possible transfer of knowledge from SF6 applications to systems filled with eco-efficient gases. Furthermore, the contribution provides insights regarding typical phase-resolved partial discharge (PRPD) patterns of typical defects. The experiments are conducted in a representative eco-efficient gas mixture consisting of 3.5 mol-% fluoronitrile (C4-FN) with the background gases carbon dioxide 86.5 mol-% (CO2) and 10.0 mol-% oxygen (O2). A comparison of the results in eco-efficient gases with investigations in SF6 and in pure CO2 is carried out. Different electrical field strengths, evoked from different voltages above the inception voltage are investigated. Comparative investigations are carried out on two different electrode arrangements. On the one hand, a disturbed weakly inhomogeneous field is replicated by a plate electrode on HV potential and a sphere electrode with a needle tip on ground potential. On the other hand, a free-moving metallic particle can be analysed in an arrangement consisting of a bowl-like ground electrode and a sphere electrode on HV potential. The presented PD measurement methods and devices are based on typical methods used in practical applications. For one, a measurement in accordance with IEC 60270 is carried out. The signals are processed with the measurement system MPD800. Time-synchronously, the signal in the ultra-high frequency (UHF) range is decoupled by an UHF sensor directly connected to the test gas compartment and processed by the UHF800 measurement system. Furthermore, an overview of the PRPD patterns is given for the free-moving metallic particle and the fixed protrusion on ground potential at different electrical field strengths in eco-efficient gas mixtures including C4-FN and in SF6. The PD measurement in accordance with IEC 60270 and in the UHF range established in SF6 can be also used in eco-efficient gases or gas mixtures. PRPD patterns recorded at a fixed protrusion on ground potential differ in SF6 and in a C4-FN gas mixture. In contrast, the PRPD patterns of a free-moving metallic particle at inception voltage are almost independent from the gas.