Seasonic S12II: 330W to 500W of Silence

Temperatures, Fan Speed and Acoustics




Both temperature curves appear similar, and naturally the 500W version gets hotter. If you compare the two power supplies at similar loads in terms of Watts, the internal temperatures are almost the exact same in most cases. It's only once the 500W model exceeds 330W (66% load) that it clearly gets warmer. The third heatsink gets quite hot on the 500W unit, reaching 80°C at maximum load. This heatsink is located in the middle, which is something of a dead spot in terms of airflow and that probably accounts for the higher temperature. We have seen worse, but the still rising temperature suggests that the 500W power supply may not survive long in higher temperatures running at full load.



In contrast, when testing at normal room temperatures the middle heatsink on the 500W version only reaches 72°C. The small 330W stays under 60°C and should not have any difficulties regardless of operating environment (within reason).



If you're wondering what happened to the results, please direct your eyes towards the lower reaches of the charts. The 330W Seasonic reaches a maximum noise level of 25dB(A), while the 500W achieves an earsplitting 28dB(A). It's not easy to describe the noise of the fans since there simply isn't much to hear. The fans are whisper quiet and about the only thing you can hear is the sound of moving air if you hold your ear right next to the power supply. Quiet fans usually mean very little airflow, and without a proper design this could be problematic. However, as we have already seen in the temperature graphs there weren't any serious problems during stress tests lasting over six hours.



The 330W S12II shows a very slow rotating fan that only reaches 1350 RPM, which helps to explain the low noise levels. The 500W model starts at around 850 RPM as well, but fan speed begins to increase passed the 50% load mark and reaches its maximum speed in stress testing at the 70% load mark. At normal room temperatures, the full speed is only reached at 100% load, so for the vast majority of users the fan will remain extremely quiet during use.