This time we made more detailed tests, starting from 85 W and increasing load little by little until we could see the maximum amount of power we could extract from the reviewed unit.
If you add all the powers listed for each test you may find a value different from what is posted under “Total†below. Since each output can have a slight variation (e.g. +5 V output working at 5.10 V), the actual total amount of power being delivered is slightly different from the calculated value. On the “Total†row we are using the real amount of power being delivered, as measured by our load tester.
The +12VA and +12VB inputs listed below are the two +12 V independent inputs from our load tester. During this test +12VA input was connected to the power supply “+12V1†rail, while +12VB was connected to the power supply “+12V2†rail (EPS12V connector).
The Cooler Master eXtreme Power Plus 600 W, like the 550 W model from the same series, can’t deliver its labeled wattage. The power supply immediately burned when we tried to run our 600 W load pattern (what would be our test number 22). Inspecting the power supply after it burned we discovered that the component that failed was one of the switching transistors. It is also very important to note that due to the huge difference between what we were supposed to see at the +12 V output and the actual voltage being delivered by the power supply (e.g., +11.25 V during test number 21), the total wattage delivered by the power supply was way lower than it should be. For instance, the load pattern used during test 21 was supposed to extract 575 W from the power supply, but it was delivering 547.3 W during this test.
Efficiency peaked at 77.6% during test eight, with the unit delivering around 245 W, and reached its lowest point at 69.2%, with the unit delivering 84.0 W.
Voltage regulation was bad, with the power supply not being able to keep the +12 V output inside its correct value from test 18 (480 W) on. Therefore, it is only safe to pull up to 450 W from this power supply – above this value this power supply can damage components from your computer.
Noise and ripple levels, on the other hand, were very low at all times. During test 21 we saw a noise level of 33 mV at +12VA, 36.4 mV at +12VB, 19.2 mV at +5 V, 15.2 mV at +3.3 V, 16.6 mV at +5VSB and 35.4 mV at -12 V. As we always point out, the limits are 120 mV for +12 V and -12 V outputs, and 50 mV for +5 V and +3.3 V outputs, and all numbers are peak-to-peak figures.
Conclusions
Why manufacturers like Cooler Master are still carrying power supplies with fake wattages is a mystery to us. We know that this is a very low-end power supply, but this doesn’t give the manufacturer the right to lie. This unit should be labeled as a 450 W unit and sold for half of its price. Being labeled as a 600 W product and sold for USD 70, it is a complete rip-off.
If you pull more than 450 W from this product it will offer real risk to your computer, plus it presents a lousy efficiency between 69.2% and 77.6%.
