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, are not sufficient, nor does it accurately reflect the performance of the power supply.
These power supply testers exert minimal load on the power supply to see what the results of the Cooler Master GX III Gold 850W is. The initial consumption was 3.2W, which indicates the basic load-free power consumption of the power supply is excellent. Independent sources with professional load testing equipment showed the Cooler Master GX III Gold 850W delivered very good efficiency for its class and acceptable voltage regulation and ripple across all rails. The power supply has an 80 Plus Gold rating and Cybenetics Platinum certification.
Voltages with minimal load are accurate, which is a basic requirement of power supplies out of the box. This power supply is ATX 3.0 compliant and officially supports Alternative Sleep Mode with 100 to 150ms PG specifications, and this is indicative of the 120ms power good signal from the tester. The ATX design specifications state a PSU's PG is required to be between 100ms and 500ms, with 250ms maximum for Non-Alternative Sleep Mode and 150ms for Alternative Sleep Mode.
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 GX III Gold 850W has active PFC, and the power factor will approach 0.99 with a nominal load.
The Cooler Master GX III Gold 850W has fairly quiet fan operation. This is a semi-passive model and the fan will only turn on at 40% load or above. Under minor loads, the power supply is literally silent, scoring 0/10 where 0 is silent and 10 is loud. Under more normal usage, the power supply still did not make too much noise, coming in at 3.0/10 in my subjective opinion. The Cooler Master GX III Gold 850W has a Cybenetics LAMBDA A- certification for sound. The power supply can definitely find a home in a silent computer.
Cooler Master provided this product to APH Networks for the purpose of evaluation.
The Cooler Master GX III Gold 850W is a decent ATX 3.0 desktop power supply overall. The quality of the work internally was seemingly quite good with an appropriate components selection for its class even though the OEM is fairly new to desktop power supplies. This semi-passive PSU is reasonably quiet under load even when the fan kicks in. Furthermore, the 10-year warranty will back up the reliability of these units. The 80 Plus Gold and Cybenetics Platinum certification efficiency ratings demonstrate its performance. It is designed to meet ATX 3.0 and PCIe 5.0 standards, which is fitting for modern builds. The Cooler Master GX III Gold 850W comes in at $165 at press time, which is on the pricey side, especially when compared against other models in its class. All in all, if you are looking for a new modular power supply, the Cooler Master GX III Gold 850W is a decent choice if the price can be dropped to be more in line with the competition.
Page Index
1. Introduction, Packaging, Specifications
2. Physical Look - Outside
3. Physical Look - Inside
4. Minor Tests and Conclusion
