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 Cougar PowerX 550W power supply, we can test it to the maximum.
The above tests represent typical loads that we have measured from various systems and are meant to give a rough idea of where your computer might fall in line with our tests. Please keep in mind that each system is different and actual loads can vary greatly even with similar hardware.
Let's start by taking a look at the voltages to see how well this unit did during testing. Starting with the 121V rail, we see 2% regulation from start to finish with a total drop of .25V. 12V2 fared slightly better, showing 2% regulation from start to finish with a total drop of .23V. The 5V rail managed to stay within 2% of specification with a total drop of .04V from start to finish. Moving towards the 3.3V rail, we see that regulation was within 3% of specification with a total voltage drop of .06V.
DC Output quality for the Cougar PowerX 550W was good and well within specifications. During Test 1, we saw 12mV of noise on our scope. When we increased the loads in Test 2, the ripple climbed to 14mV at around half load. During Test 3 under a load of 550W, the oscilloscope showed a maximum of 31mV on noise on the 12V rail.
The Cougar PowerX 550W is rated for 80 PLUS Bronze efficiency. This means that the power supply must perform at 82%/85%/82% efficiency at 20%/50%/100% loads respectively. As you can see, the PowerX 550W passed on our bench, and wasn't close to failing at any point.
Remember that I stated at the beginning of this review that in no way would we be able to define this power supply as an industry leader, a game changer, or anything revolutionary. It is strictly a budget power supply that gives you solid performance beyond the $30 no-name junk units that may or may not last more than six months. It does a very good job at doing this too.
The performance results are nothing to brag about, but having voltage regulation at no worse than 3% in a budget unit is a very nice thing. I have to admit that I am pleased with the noise suppression on the 12V rail too as it is much better than I expected. The efficiency is just what you would expect as it starts falling off fast as you near full load for this Bronze rated unit.
The real deal with this unit though is the price and the fact that it is dirt cheap. When it comes to the US market at $70, it will be a steal and it is only a matter of time before it drops in price a little bit making it even more of a bargain.