Cross-Load Tests & Infrared Images
Our cross-load tests are described in detail here.
To generate the following charts, we set our loaders to auto mode through our custom-made software before trying more than 25,000 possible load combinations with the +12V, 5V and 3.3V rails. The load regulation deviations in each of the charts below were calculated by taking the nominal values of the rails (12V, 5V and 3.3V) as point zero. The ambient temperature was between at 30°C (86°F) to 32°C (89.6°F).
Load Regulation Charts
Across much of its operating range, the RM850x delivers 90-92% efficiency.
We applied half-load for 10 minutes with the PSU's top cover and cooling fan removed before taking photos with our modified FLIR E4 camera that delivers 320x240 IR resolution (76,800 pixels).
Our IR shots show that the NTC thermistor gets quite hot (close to 82°C) after barely 10 minutes. Obviously, a bypass relay was needed to keep the thermistor cool while the PSU is in use.
Moreover, filtering caps between the +12V boards look like they run hot when the fan isn't spinning, which would be the case during normal use. At least they belong to Chemi-Con's higher-quality KZH series and not the entry-level KZE family. The bulk caps also see higher temperatures than we expected, mostly because of heat dissipated by the nearby PFC FETs and boost diode.
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