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, 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 9.2W as measured by our wall meter unit, indicating the basic load-free power consumption of the power supply was very good. The efficiency, voltage regulation, and voltage ripple of the SilverStone Decathlon DA850 Gold 850W has yet to be tested by independent websites at the time of release. This is an 80 Plus Gold certified power supply.
Voltages with minimal load are generally accurate, which is a basic requirement of power supplies out of the box. In this situation, all were all within 3%. The PG or Power Good delay came in at 320ms, which follows an older ATX specification. For reference, the design specifications are supposed to be between 100ms and 500ms. However, 250ms maximum is needed 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, or active power (P, measured in watts), reactive power (Q, denoted as VA-R), and total apparent power (S, written as VA). While they all have the same physical units, it is not the same thing as aforementioned. Reactive power actually plays an important role in large power systems for keeping the voltage stable. If there is an insufficient amount of reactive power being injected into an electrical bus, the voltage will become unstable and unable to supply active power to the desired loads. At the distribution level though, reactive power is essentially wasted power, since it does not do any work. Thus, what we want in the case of our power supply unit is active power with as little 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 is easily calculated by P divided by S. The ideal value is 1.00, and this is where active PFC comes in. The SilverStone Decathlon DA850 Gold 850W has an APFC circuit, and the power factor should approach 0.99 under a nominal load.
The SilverStone Decathlon DA850 Gold 850W is a moderately quiet power supply. Under regular loads up to 50%, the Decathlon DA850 is low noise. Personally, I found the fan to be pretty good, even when it ramps up. On a scale from 0 to 10 where 0 is silent and 10 is a rock concert with fireworks, I would rate the SilverStone Decathlon DA850 Gold 850W at 1.5/10 acoustically under nominal loads, because the fan spins really slowly. The fan is out of the way to approximately 50% of its maximum speed and will become a little more audible at full load. If you are a silent PC enthusiast, the SilverStone Decathlon DA850 Gold 850W is a good choice thanks to SilverStone's great fan curve profile.
SilverStone provided this product to APH Networks for the purpose of evaluation.
The SilverStone Decathlon DA850 Gold 850W is a solid power supply unit that, once again, shows the benefits of remastering an older product. It is only 14cm long, which is great if you have a small case. Open it up, and you will find a solid selection of internal components built by reputable OEM Channel Well Technology. All the capacitors are Japanese made, which is preferable. Power the Decathlon DA850 Gold 850W on and you got a fluid dynamic bearing fan with a very low speed fan profile for quiet operation. However. its tested PG follows an older ATX specification and it only comes with a 3-year warranty, which could benefit from being at least 5 years for a power supply of this class. For an MSRP of $136, this is quite reasonable for a solidly built 80 Plus Gold certified, compact fully modular PSU.
1. Introduction, Packaging, Specifications
2. Physical Look - Outside
3. Physical Look - Inside
4. Minor Tests and Conclusion