Seasonic Prime Ultra Platinum 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

One spur comes dangerously close to the limit. But it doesn't go over, so Seasonic's SSR-1000PD Ultra passes this test successfully.

EMI Results - Peak Detector

Again, we observe passing performance.

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  • Th_Redman
    I notice you didn't give it an award rating...what gives, if you present it with such high praise?
  • Aris_Mp
    It has an award. It is just not shown, yet :)
  • Kennyy Evony
    Lets all hope it doesn't kill your motherboard and all components like my SeaSonic did while only operating 1 year under light workloads. No matter how much change they make to PSU I would not trust a brand that would allow catastrophic results in using their products AND not accept responsibility for the loss.