Seasonic Focus GX-1000 V4 ATX v3.1 PSU Review

Average Noise

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avg_noise_230V

The PSU’s average noise output is close to 28 dBA at both voltage inputs, so it is low enough but not as low as other offerings in this Wattage category.

Fan Noise & Speed Maps @ 28-32 °C – 115V

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CL_Fan_Speed

The semi-passive operation is between 60W and 85W on the minor rails, with the load on the 12V rail up to 350W. Apparently, the programming of the MCU that controls the fan’s speed goes wild with the load pattern that I use in these tests, but this shouldn’t be the case. I like that I can get the worst-case scenario through these tests, and not the ideal one, because in real life, a PSU will be treated with a wide variety of load patterns, depending on each user’s system and utilization.

Moreover, users need to understand that most fan speed profiles also (indirectly) consider the load applied to the minor rails through the appropriate thermal sensors because the respective DC-DC converters lack the appropriate heatsinks, so they rely on active cooling to lower their operating temperatures. The DC-DC converters, as their name implies, receive DC input and not AC, so the AC input voltage doesn’t affect their efficiency and thermal loads. This is why when you push them to the maximum, the fan’s speed will be regulated at the same levels whether you have 115V or 230V input, and this is why in many modern PSUs, the 115V and 230V fan noise speed and fan speed maps are identical. There can be major differences only when other parts of the PSU, except the DC-DC converters, get way hotter at 115V compared to 230V input. These parts are typically up to the APFC converter, where the input voltage is boosted at around 385VDC at the APFC converter’s output.

Fan Noise & Speed Maps @ 28-32 °C – 230V

CL_Fan_Noise

CL_Fan_Speed

The 230V fan noise profile is similar to the 115V one.