Setup & Testing
To test power supplies, we believe that creating real-world circumstances and conditions are important to consumers who need to relate to what they would use and experience in a computer system setup. Consequently, our methodology is fairly straightforward: we assemble the most power-hungry components we can muster, hook up the power supply, and take measurements at idle and load using a Kill-A-Watt meter for wattage, and a digital multimeter for voltage output and fluctuations. Unfortunately our new oscilloscope has not yet arrived, so we apologize we’re not able to test DC output quality on the unit today.
To break this down a bit further, we conduct primarily 4 tests:
- Idle: The system sits at idle in Windows
- CPU Load: In this test we run concurrent instances of Prime95 on all CPU cores
- GPU Load: In this test we run FurMark, as it recognizes SLI and CrossFire setups and loads the GPUs very heavily with maximum settings
- System Load: In this test we run concurrent instances of Prime95 and FurMark to draw the maximum amount of wattage possible
The Xigmatek NRP-HC1201 is a monster and with that much available power it may be difficult for most users to muster something that can push it that hard. However, we’re pulling out all the stops today, as we’ll start with an Intel Core i7 quad core processor that is very highly overclocked. It is cooled with a exceedingly large thermoelectric (TEC/Peltier) watercooling setup that also draws a massive amount of power on the system, far more than any traditional cooling method. We then connect three graphics cards in Crossfire/SLI to tax the power supply even further. This setup can easily pull down some extremely high wattage, pushing this unit very hard, and far more than even the most hardcore systems that users would have at the best of times in a real-world setup.
When examining the results we are looking for the voltage output and any fluctuations that might occur. The current ATX specifications allow for the following fluctuations in voltage outputs, and these represent a 3% variance:
- 3.3V Rail: 3.135V – 3.465V allowable
- 5V Rail: 4.75V – 5.25V allowable
- 12V Rail: 11.4V – 12.6V allowable
Below are the results:
When we look at the voltage regulation results below, this is where the NRP-HC1201 1200w really stands out; it posts very good results across the testing spectrum, even on the full system test. There were no fluctuations in the readings, and showing a deviation of only 0.06V (0.5%) on the +12V rails at full load is an outstanding result.
One last note here relates to the noise produced by the unit. As we know, the higher RPMs a fan speeds, the louder the noise, but then also the cooler the temperatures. It is an ongoing balancing act between noise and cooling for just about any mechanical component in a system. To that end, it seems that the NRP-HC1201 is able to maintain lower sound levels by having the fan spin at rather low RPMs, but when it ramps up the fan is audible. It is not very loud but it’s not the quietest we’ve tested either. Chances are, however, that your graphics card fan will most certainly drown out the noise inside a case if you’re running full tilt.