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 higher than that of the Kingwin LZP-550, we can test it to the maximum.
While there aren't quite as many results here as we are used to seeing with the higher output units, there is still plenty of good information on just how well the LZP-550 performs. Voltage regulation is within 3% or better with the 5V rail just barely going outside of the 2% mark at the start. The 12V rail stays within 2% regulation and the 3V rail is within 1% of specification. As the loads increase, the voltage regulation gets better all the way up to the full load test. At full load, both the 12V and 3.3V rails are within 1% and the 5V tightens up to 2% regulation.
Noise on the LZP-550 faired rather well. During Test 1, we recorded a maximum of 23mV on the 12V rail. Just as you would expect, this increased as the load on the unit increased. This crept up to 29mV peak to peak during Test 2 and eventually ended up at 34mV under full load. While these aren't the most spectacular results that we have ever seen out of a power supply to date, they are still very good results.
One of the main highlights of the LZP-550 is that it is capable of performing at 80Plus Platinum levels of efficiency. As you can see from the results above, the Kingwin LZP-550 delivered just as it said it would. Keep in mind that in order to achieve the 80Plus Platinum certification, the power supply must perform at 90%/92%/89% efficiency at 20%/50%/100% loads. The LZP-550 excelled at this and never even came close to failing during any of the tests.
Kingwin has done an excellent job with the LZP-550 power supply. While the unit might simply be a reference unit from Super Flower, the unit wouldn't be available in the USA if not for Kingwin. The LZP-550 scores excellent from start to finish. The list of cables and connectors, both native and modular, ensure that the power supply is capable of fulfilling the needs of almost anyone who needs a 550W power supply.
Kingwin's LZP-550 also performs quite well with great voltage regulation, good DC output quality and excellent efficiency. With the ever-increasing cost of electricity, the LZP-550 becomes even more attractive despite the $150 price tag, especially if you make use of it for the full five years that it is warrantied for.