Together with an APC SmartUPS SC620 the power supply worked at loads up to 385W when powered by the mains. They switched to the batteries normally but were not stable – the UPS could work more than 1 minute on the battery only at loads up to 300W. So, there is no difference from the Xigmatek unit in this test.
Now we’ve come to the most interesting test. Thermaltake’s power supplies based on this platform demonstrated very poor results before. The Xigmatek has shown good performance in this test – perhaps Thermaltake’s PSUs have improved, too?
They have improved indeed. The +12V voltage has excellent stability throughout the entire load range. The +5.5V voltage is within a 4% deflection (while the industry standard allows a 5% deflection). The +3.3V voltage is the only one to violate the allowable limit, but only under extremely high loads which are impossible in modern computers (a typical combined load on the +5V and +3.3V rails is only 50-60W in a modern PC).
Output Voltage Ripple
The voltage ripple is higher on the +12V rail than with the Xigmatek PSU, but acceptable. The +5V voltage is within the norm, too. There are spikes on the +3.3V rail above the permissible limit, but that shouldn’t be a problem. Thermaltake’s 1500W units I tested before had much stronger pulsations.
Fan Speed Management
The PSU is equipped with a 140x140x25mm Yate Loon D14BH-12 fan. The Yate Loon site says the fan has a rated speed of 2800rpm, but a similar fan works at a lower speed in the above-discussed PSU from Xigmatek.
The Thermaltake is noisier than the Xigmatek unit but the difference in fan speed is small and must be due to the variation in the real parameters of employed components. The Thermaltake also has a pretty-looking but aerodynamically poor grid of the fan. The PSU is not silent but quite comfortable, considering its huge wattage.
Efficiency and Power Factor
The PSU is up to 86% efficient at medium loads and 80% efficient at high loads. It has the same result as the Xigmatek PSU.
+5Vsb Standby Source
The standby source copes with loads up to 3.5A, which is quite normal for today. Its voltage changes greatly depending on load, but does not violate the permissible limits.
I can note two things here. First, the reputation of the Thermaltake Toughpower W0171 power supply is restored. And second, it differs but slightly from the Xigmatek NRP-HC1501 model. If you think your computer needs a power supply of such a high wattage, you can buy a W0171 without any fear: it is a high-quality product with stable operation and comfortable level of noise.