On our reviews with HX750W and HX850W power supplies we've seen a high noise level on the +5VSB (standby) output surpassing the 50 mV limit while the power supply was delivering 20%, 40% and 60% from its maximum capacity. Below you can see the screenshots we got with HX750W during tests number one (20% load, i.e. 150 W, with +5VSB delivering 1 A/5 W), two (40% load, i.e. 300 W, with +5VSB delivering 1.5 A/7.5 W) and three (60% load, i.e. 450 W, with +5VSB delivering 2 A/10 W). During tests number four and five noise was below the maximum allowed.

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Figure 1: +5VSB during test one.

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Figure 2: +5VSB during test two.

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Figure 3: +5VSB during test three. 

Worried about our findings, Corsair tested HX750W on a Chroma 8000 load tester (a far more advanced system than our SunMoon SM-268) configured with the same load patterns we used. The results for +5VSB noise were very different, as you can see on the screenshots below (maximum noise of only 13.8 mV). The only explanation we have is that somehow our equipment interfered with the outputs. This way any criticism regarding the +5VSB from these two power supplies we posted on the past should not be considered.

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Figure 4: +5VSB during test one, Corsair testing.

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Figure 5: +5VSB during test two, Corsair testing.

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Figure 6: +5VSB during test three, Corsair testing.

Originally at http://www.hardwaresecrets.com/blog/152

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