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
The efficiency sweet spot is between 160W and 410W of load on the +12V rail (while load on the minor rails is lower than 50-60W). In most of its operating range, the SSR-750FX delivers 85-90% efficiency.
We applied half-load for 10 minutes with the PSU's top cover, along with its cooling fan, removed before taking photos with our modified FLIR E4 camera that delivers 320x240 IR resolution (76,800 pixels).
Temperatures inside the PSU are quite low, despite the half-load we applied for a 10-minute period. This indicates that Seasonic could make its fan profile less aggressive if it wanted to. But the company's engineers are probably playing it safe in order to offer a 10-year warranty.
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