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Corsair HX1050 1050W Power Supply Review

Testing (Continued):

Efficiency and Power Factor:

Efficiency is a measure of the ATX power supplies ability to minimize losses during the conversion of the AC mains voltage into multiple DC rails. It is a simple ratio of output power measured in watts over input power measured in watts expressed as a percentage. It has no affect whatsoever on the power supply’s ability to power a PC but with higher efficiency comes less heat and lower utility bills; it’s also “green” and friendlier to the environment which is the driving force behind the 80 Plus certification program.

Power factor is a strange beast that’s difficult to fully explain without the use of complex AC theory, so let’s keep it simple. Power factor doesn’t have a unit of measurement - it’s a simple number from 0 to 1 that is concerned with the way various loads consume power and the nearer to unity the better. It is closely linked to 80 Plus certification because low power factors imply wasted energy that the normal domestic consumer does not get charged for, but the utility companies still have to generate.

Supply at 110VAC:

Corsair HX1050 1050W (CMPSU-1050HX) Efficiency & Power Factor

Supply = 110VAC/50Hz

DC Load (W)

0

237

535

1080

DC Load As A Percent Of Max (%)

N/A

22.5

51

103

Efficiency (%)

N/A

86

86

83

Power Factor (PF)

0.78

0.98

0.99

0.99

The Corsair HX1050 produced a fairly typical set of results in this section that fell a little short of the 80 Plus Silver requirements (85%, 88% and 85% efficiency at 20%, 50% and 100% DC loading) following the OCC power supply testing methodology. The OCC power supply testing methodology doesn't exactly replicate the rail loadings and a shortfall of one or two percent isn't unusual so it would be unfair to mark the power supply (or any other that produced similar results) down in this section. Power factor levels are rarely if ever a problem in high end power supplies, especially with a 110VAC supply, and the HX1050 easily kept the level above the required 0.9 mark at 50% DC loading.

Supply at 230VAC:

Corsair HX1050 1050W (CMPSU-1050HX) Efficiency & Power Factor

Supply = 230VAC/50Hz

DC Load (W)

0

240

545

1074

DC Load As A Percent Of Maximum

N/A

23

52

102

Efficiency (%)

N/A

87

89

85

Power Factor (PF)

0.24

0.93

0.97

0.98

The performance of the HX1050 with a 230VAC mains supply is also typical of many other power supplies in this class with better efficiency and very slightly lower power factor levels. The efficiency levels meet the 80 Plus Silver requirements with 87%, 89% and 85% but as with most power supplies the certificate is valid for 117VAC and not 230VAC. Power factor levels are up there with other units tested by OCC and a maximum efficiency of 89% isn't too shoddy.

No problems in this section, so let's move on.

AC Ripple On DC Outputs:

I have consistently found the AC ripple levels on the DC rails to be more or less equal with an 110VAC or 230VAC mains supply. The results given below are for 230VAC only but I will continue to check the levels at 110VAC during testing and publish them below if there are any significant differences.

AC ripple/noise on the +3V3 rail at 230VAC

Oscilloscope settings: Amplitude = 10mv/div, Timebase = 20mS/div

AC ripple/noise on the +5V0 rail at 230VAC

Oscilloscope settings: Amplitude = 10mv/div, Timebase = 20mS/div

AC ripple/noise on the +12V rail at 230VAC

Oscilloscope settings: Amplitude = 10mv/div, Timebase = 20mS/div

AC ripple/noise on the -12V rail at 230VAC

Oscilloscope settings: Amplitude = 10mv/div, Timebase = 20mS/div

AC ripple/noise on the +5VSB rail at 230VAC

Oscilloscope settings: Amplitude = 10mv/div, Timebase = 20mS/div

Corsair HX1050 1050W (CMPSU-1050HX) AC Ripple/Noise

Supply = 233VAC/50Hz DC Loading = 1074W

DC Rail

+3V3

+5V0

+12V

-12V0

+5VSB

ATX12 Max (mV p-p)

50

50

120

120

50

Ripple (mV p-p)

32

37

64

83

27

Pass/Fail

Pass

Pass

Pass

Pass

Pass

The Corsair HX1050 produced a satisfactory set of results in this section with the noise/ripple levels remaining within the limits set down by the ATX12V V2.2 specification at all times. The levels are it must be said a little higher than some other power supplies tested by OCC in this class, but they are within specification and whilst not a problem, they could be lower.