The P550B gets last place in this chart. This doesn’t sound weird, given its bad ripple suppression at 12V and the equally bad transient response performance.
The graph below depicts the cooling fan's average noise over the PSU's operating range, with an ambient temperature between 30 to 32 degrees Celsius (86 to 89.6 degrees Fahrenheit).
Low efficiency means increased thermal loads, so the fan has to work hard to protect and cool down the PSU. This translates to high noise output. The P550B is noisy, so if you want to build a quiet system, remove it from your list.
The following graph shows the PSU's average efficiency throughout its operating range with an ambient temperature close to 30 degrees Celsius.
This is a low-efficiency platform. If you need higher efficiency and lower thermal loads, better get something else.
Power Factor Rating
The following graph shows the PSU's average power factor reading throughout its operating range with an ambient temperature close to 30 degrees Celsius.
The power factor with 115V input is high enough. On the contrary, it is bottom low with 230V.
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