Our load tests utilize a couple of FAST ATE active load testers and a variety of other equipment such as an oscilloscope, power conditioner, temperature probe and a power consumption meter. You can read more about our standard testing approach here.
The tests performed are based around six conceivable setups that are out there and progressively load down the PSU up to the power supply's limits or 1000W, whichever comes first. Since our test equipment's limits are equal to that of Topower TOP-1000WG, we can test it to the maximum.
Starting off with the voltages, we see that the TOP-1000WG performed rather well. With the exception of the 12V2 rail, everything managed to stay within 2% of specifications and 12V2 just barely snuck into the 3% range at the start. The 3.3V and 5V rails performed on par with what we saw from the 12V rails. While there was a little more fluctuation in voltage from start to finish than we are used to seeing, everything stayed well within ATX specifications.
DC output quality is certainly where the Nano Series from Topower excels. The TOP-1000WG had hardly any noise on the 12V rails at the start, showing on 6mV peak to peak. It isn't until we upped the load on the power supply to about 50% that we finally noticed some noise on the scope at 15mV peak to peak. Ripple continued to climb until we finally hit full load. Even at full load, the TOP-1000WG only showed 35mV of noise on the 12V rail.
The TOP-1000WG performed quite well in the area of efficiency too. While the power supply was cutting it a little close at the start of the tests, that quickly changed as the loads were increased. At about 50% load the efficiency was right where you would expect. The impressive part was the results under full load where the TOP-1000WG was still showing above 89% efficiency.
Topower's TOP-1000WG performed rather well in our tests. Voltage regulation was within 3% across the board, DC output quality was great and the efficiency of the unit was also wonderful. The power supply comes with a great selection of connectors and cables for a natively wired unit and most will be hard pressed to find a need for additional cables or connectors. Topping off the list of things that the TOP-1000WG has going for it is the price. At a price of right around $160, it is one of the cheapest 80Plus Gold rated units on the market. Couple that with the solid performance the power supply offers and you've got a bargain that is hard to beat.
Unfortunately the unit isn't without its flaws and shortcomings. Right from the start we saw that the output on each of the 12V rails was a little bit low and became even more apparent once we noticed that the 12V rails shared loads between PCI-E and other devices. As we often see with power supplies that perform well, but are cheaper than the competition, the TOP-1000WG sacrifices a few features for the price point. In this case we lose modular cables, over temperature protection and a 50C power rating. Topower also only offers a three year warranty for the unit.