Seasonic Prime Ultra Titanium 1000W PSU Review

EMC Pre-Compliance Testing

EMC, EMI & EMS Acronyms

Electromagnetic Compatibility (EMC): The ability of a device to operate properly in its environment without disrupting the operation of other close-by devices.

Electromagnetic Interference (EMI): This represents the electromagnetic energy a device emits, which can cause problems in other close-by devices if it is too high.

Electromagnetic Immunity (EMS): Tolerance to electromagnetic emissions.

Equipment & Standards

To properly measure the EMI that a device emits, you need special equipment defined by the CISPR 16-1-1 specification. To learn more about our EMI testing equipment, please check out How We Test Power Supply Units.

In order to minimize EMI noise, some standards have been established. The corresponding standards for Information Technology products are CISPR 22 and its derivative EN 55022. In the EU, every product featuring the "CE" marking has to comply with EN 55022. Both CISPR 22 and EN 55022 divide devices into two classes, A and B. B-class equipment is for domestic environments, so its allowed EMI emissions are significantly lower than for A-class devices.

CISPR / EN55022 Limits
CISRP 22/ EN 55022 Class A Conducted EMI Limit
Frequency of Emission (MHz)Conducted Limit (dBuV)
Quasi-peakAverage
0.15 - 0.507966
0.50 - 30.07360
CISPR 22/ EN 55022 Class B Conducted EMI Limit
Frequency of Emission (MHz)Conducted Limit (dBuV)
Quasi-peakAverage
0.15 - 0.5066 - 5656 - 46
0.50 - 5.005646
5.00 - 30.006050

EMI Results - Average Detector

Our equipment picks up three fairly high spurs, though they're below the defined thresholds.

EMI Results - Peak Detector

We observe four spikes in this test, all of which top out below the red line.

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6 comments
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  • jaber2
    Boy that is cheap
  • Nintendork
    I really wish companies focus on 300-550w Titanium PSU's, who the hell uses SLI/CF this days? Market is going multiCCX gpu's in the upcoming years.

    A Ryzen 2700X + Vega56/1070ti systems won't even draw past 375-400w. Most gaming PC's will stay at below 250w. Meanwhile for people who keep their PC 24/7 most of the time in idle, a contained PSU at titanium with 90% efficiency at 10% load is awesome.

    My Bronze Seasonic S12-II 520w seems to be a gem with 82% efficiency at 10% load when most higher grade PSU's (gold/platinum) ignore this since they only need to comply with 85-90% minimum @20% load and then crapify to hell once you reach 15-10% load.
  • Armando_0818
    Just an FYI. CISPR 22 is no longer used. It has been updated to CISPR 32.

    Regards
  • Aris_Mp
    Thank you! The limits are the same though for the conducted emissions that we measure and in general the products that pass the CISPR22 are likely to pass testing against CIPSR32.

    The CISPR22 was for information technology equipment while CIPSR32 is for multimedia stuff in general.
  • zodiacfml
    Would you mind reviewing crypto PSUs from China? I have this Senlifang 2000W with 95 PLUS Gold sticker on it.
    I don't expect such efficiency until one day I plugged it to a system which previously has an 80 Plus Bronze - 650W PSU. The consumption on both PSUs are almost the same!
    Adding to that, I've read somewhere that it is easier to have higher efficiencies on high wattage PSUs which I guess adds more credibility to the Senlifang PSU efficiency claims.
  • Aris_Mp
    I don't believe that any of those manufacturers would be willing to send a review sample to me (or to any other PSU reviewer with proper equipment). The majority of them sell overrated stuff using bogus labels. Just be extra careful with those unknown PSU brands promising super high efficiency and wattage.