Even if only barely, the Corsair CX430M does meet the 80Plus Bronze certification efficiency requirements. The efficiency of the power supply never dropped below 82% and reached up to 85.1% under nominal load while it was being powered by an 110V A/C source, which is just shy of the 85% limit it had to reach for the 80Plus Bronze certification.
The low capacity of the power supply, combined with the good efficiency, allows it to generate very little amounts of heat. As little amounts of heat need to be dissipated, the cooling fan does not have to spin too fast, even if the heatsinks sport little surface area. This combination allows the CX430M to remain virtually silent across its entire capacity range, reaching audible figures only after running at >80% load.
As the power capacity of the CX430M is rather low, we did not expect great changes in temperature. Truly, the exhaust air temperature of the unit is less than a single Celsius degree higher than that of the ambient air while the power supply is mildly loaded. As the load increases, so does the temperature delta, reaching however only up to 5.6°C at maximum load.