Page 4 - Minor Tests and Conclusion
Power supplies are interesting products, because often, reviews of products in this category are conducted and tested in methods that make it difficult to distinguish one power supply from another. Many aspects must be taken into consideration. Certain criteria consist of efficiency, noise, power ripples, and of course the ability to pull out the rated specifications. Because many cannot afford such equipment to obtain results regarding those aspects, articles covering power supplies often come out with less than adequate and acceptable information. As this is a product report -- not a review -- what we are doing is a close examination of the power supply and the internal hardware and build. But what we can do for you is do some minor testing with the results we can present to you with and let other review sites with professional equipment show you the actual test results. We are not going to try to create useless test results by installing the power supply into the latest gaming rig and try to take readings from that, as this is not even remotely the correct way to test power supply units. We understand that many websites do that as a means of load testing, but the results, even if you use an oscilloscope and multimeter at each output location, it is not sufficient, nor does it accurately reflect the performance of the power supply.
Using our power supply tester which exerts minimal load on the power supply, the initial consumption was 8.2W as measured by our wall meter unit -- indicating that the basic load-free power consumption of the power supply is good. Independent reviews from websites with professional load testing equipment showed the Cooler Master MWE 650 White V2 650W delivered good efficiency, but there are not many other reviews of this unit elsewhere.
Voltages with minimal load are generally accurate, which is a basic requirement of power supplies out of the box. In this situation all are all within 2%. The PG (Power Good) delay is very good compared to old power supplies, but out of the specification at 80ms. The ATX standard specification states it should be within 100ms to 500ms.
Active power correction is important to correct AC load line loss. In AC power, there are three components to it; as there is a phase difference between current and voltage. This makes up the power triangle, which consists of the following: Average usable power (P, measured in watts), reactive power (Q, denoted as VA-R), and total power (S, written as VA). While they all have the same physical units, it is not the same thing as aforementioned. What we want is the average usable power with as little wasted reactive power as possible. The total power provided over the AC line is the magnitude of the two combined (sqrt(P^2+Q^2)). Power factor can then be easily calculated by P divided by S. The ideal value is 1.00, and this is where active PFC comes in. The Cooler Master MWE 650 White V2 650W has active PFC, and thus the power factor will approach 0.99 with a nominal load.
The Cooler Master MWE 650 White V2 650W is a decently quiet power supply. This fan used here is found in many other power supplies, and generally it has been good. However, Editor-in-Chief Jonathan Kwan noticed a bit of coarseness in the motor noise at higher speeds with other units, such as the XPG Core Reactor 750W. On a scale from 0 to 10 where 0 is silent and 10 is the loudest, I would rate the Cooler Master MWE 650 White V2 650W to be at 2.0/10 acoustically under nominal loads, because the fan spins slowly at lower temperatures. At the lowest temperatures the fan should be quiet or even off, but under higher loads or higher temperatures, this fan will ramp up in noise.
Cooler Master provided this product to APH Networks for the purpose of evaluation.
The Cooler Master MWE 650 White V2 650W is primarily a budget power supply for a budget build. The lack of modular cables and only 80 Plus efficiency rating are acceptable for a basic unit. However, lower-tier components are used within and the short three-year warranty means you get what you pay for. Our affiliates have yet to test the Cooler Master MWE 650 White V2 650W, so I will hold back on commenting about voltage regulation, ripple control, standby efficiency, or other performance metrics. This unit does not seem to be available in the United States and retails in Canada for $87 CAD at press time. All in all, this puts it in a similar pricing category to some other units at this wattage, but most of them offer at least an 80 Plus Bronze efficiency rating. As such, the Cooler Master MWE 650 White V2 650W seems to be a serviceable power supply, but there are potentially better options in this budget segment.
Page Index
1. Introduction, Packaging, Specifications
2. Physical Look - Outside
3. Physical Look - Inside
4. Minor Tests and Conclusion
