In Win Classic Series C 900W PSU Review

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Load Regulation, Hold-Up Time, And Inrush Current

To learn more about our PSU tests and methodology, please check out How We Test Power Supply Units. 

Primary Rails And 5VSB Load Regulation

Load Regulation testing is detailed here.

Hold-Up Time

Our hold-up time tests are described in detail here.

Our measured hold-up time is less than what's required. We expected this since the bulk caps' combined capacity is low for this unit's capacity. At least the power-good signal is accurate.

Inrush Current

For details on our inrush current testing, please click here.

The registered inrush current with both voltage inputs is low for a 900 W PSU.

Load Regulation And Efficiency Measurements

The first set of tests reveals the stability of the voltage rails and the PSU's efficiency. The applied load equals (approximately) 10 to 110 percent of the maximum load the supply can handle, in increments of 10 percentage points.

We conducted two additional tests. During the first, we stressed the two minor rails (5V and 3.3V) with a high load, while the load at +12V was only 0.1 A. This test reveals whether a PSU is Haswell-ready or not. In the second test, we determined the maximum load the +12V rail could handle with minimal load on the minor rails. 

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Test #12V5V3.3V5VSBDC/AC (Watts)EfficiencyFan SpeedFan NoiseTemps (In/Out)PF/AC Volts
15.518A1.964A1.970A1.000A89.7688.06%290 RPM21.2 dB(A)37.73 °C0.979
12.353V5.099V3.345V4.992V101.9341.76 °C115.1V
212.112A2.949A2.969A1.204A179.5891.13%315 RPM21.9 dB(A)38.10 °C0.982
12.278V5.081V3.332V4.977V197.0542.82 °C115.1V
319.101A3.456A3.493A1.410A269.8091.76%465 RPM26.5 dB(A)39.02 °C0.990
12.235V5.066V3.319V4.961V294.0443.89 °C115.1V
426.099A3.954A3.989A1.615A359.5991.68%650 RPM30.2 dB(A)40.21 °C0.994
12.201V5.052V3.307V4.945V392.2345.33 °C115.1V
532.791A4.970A5.010A1.825A449.5691.26%850 RPM33.2 dB(A)42.05 °C0.995
12.170V5.033V3.291V4.929V492.6247.49 °C115.1V
639.515A5.983A6.040A2.035A539.5690.64%1000 RPM35.2 dB(A)43.02 °C0.996
12.142V5.013V3.276V4.909V595.2748.65 °C115.1V
746.264A7.012A7.079A2.245A629.4789.85%1130 RPM36.2 dB(A)43.73 °C0.997
12.113V4.991V3.263V4.892V700.5849.60 °C115.1V
853.035A8.049A8.132A2.460A719.3888.95%1210 RPM36.7 dB(A)44.13 °C0.997
12.086V4.970V3.247V4.874V808.7850.47 °C115.1V
960.273A8.580A8.694A2.464A809.4088.12%1210 RPM36.7 dB(A)44.86 °C0.997
12.059V4.953V3.231V4.863V918.5651.54 °C115.1V
1067.280A9.117A9.230A3.099A899.1987.14%1210 RPM36.7 dB(A)45.81 °C0.997
12.032V4.937V3.217V4.832V1031.8552.88 °C115.1V
1174.919A9.138A9.261A3.108A989.0986.44%1210 RPM36.7 dB(A)46.30 °C0.997
12.005V4.925V3.206V4.823V1144.2053.70 °C115.1V
CL10.098A12.011A12.005A0.003A101.2383.44%1030 RPM35.5 dB(A)43.52 °C0.978
12.327V5.019V3.309V5.006V121.3249.41 °C115.1V
CL274.953A1.003A1.003A1.002A915.4187.79%1210 RPM36.7 dB(A)45.91 °C0.997
12.037V5.001V3.249V4.915V1042.7952.88 °C115.1V

Load regulation is mediocre and way behind the competition. In Win focused more efficiency and ripple suppression, but didn't pay enough attention to load regulation. In order to provide more than 12 V under any load, the +12V rail has a nominal voltage that exceeds 12.35 V during the 10% load test. We want all rails to be close to the voltages defined by the ATX spec, so we don't agree with overvoltage tricks.

As far as efficiency is concerned, the corresponding 80 PLUS Platinum requirement is satisfied in the 20% load test. This is not the case, however, for the 50% and full load tests, where the unit's efficiency is significantly below the specified thresholds. In general, the only positives we come away with are low noise and the PSU's ability to deliver full power under high operating temperatures. Those just aren't enough to keep us happy.

Contributing Editor

Aris Mpitziopoulos is a Contributing Editor at Tom's Hardware US, covering PSUs.

  • Dark Lord of Tech
    Does the EVGA P2 series have OTP?
  • Aris_Mp
    newer batches have according to my sources. Older ones didn't have.
  • Johan Kryger Haglert
    Terrible bang for the buck you mean.
  • Dark Lord of Tech
    18741010 said:
    newer batches have according to my sources. Older ones didn't have.

    Thank you much appreciated!!!!
  • falchard
    It's not a terrible buy. If you have a beautiful in-Win case, can you really tell yourself the best PSU for the price should be placed in there?