NZXT Performance Power 800W
Testing & Results
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.
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
In order to load up a power supply very heavily, we use a quad core processor that is highly overclocked. It is cooled with a customized thermoelectric (TEC/Peltier) watercooling setup that draws a significant amount of power. We then connect either a dual-GPU card or dual cards in Crossfire/SLI to tax the power supply even further. This setup can easily pull down some very high wattage, and can exceed the 800W power limit of this unit, so rest assured this unit will scream at the demand being placed on it. Needless to say, this should surpass what most consumers would use 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, the 3V rail deviated a bit more than we’ve seen on some other units but was stable. Similarly, the 5V showed a bit of a drop but nothing worrisome. On the full load system test, there were no fluctuations in the readings, and showing a deviation of 0.08V on the +12V rails, which is a good result.
One last note here relates to the noise produced by the unit. As we know, the higher RPMs of a fan, 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. Earlier we noted that a dual fan setup (particularly units with an 80mm fan) typically causes noise levels to be higher than a design that employs a single, larger fan. During our testing we did note that the Performance Power 800W’s fans spun up as expected to handle the higher load. The exhausting air was not terribly warm, so the fans were performing well to keep the unit cooler, but it did come at a much higher noise level. The 80mm fan was indeed the culprit, though the 120mm wasn’t silent either. Comparing it to a few other units we’ve tested, it is not very quiet, especially when loaded.