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 6.0W as measured by our wall meter unit -- indicating that the basic load-free power consumption of the power supply is excellent. Independent reviews from websites with professional load testing equipment showed the Cooler Master V850 SFX Gold 850W delivered good efficiency with low amounts of voltage ripple on the different rails.
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 at 80ms is a bit outside the ATX standard specification of 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 V850 SFX Gold 850W has active PFC, and thus the power factor will approach 0.99 with a nominal load.
The Cooler Master V850 SFX Gold 850W a low noise output power supply. With regular loads under 15%, the fan does not turn on. However, when the fan turns on, it does ramp up a bit more noticeably. Even so, this should not be too surprising considering the size and the cooling that is necessary at higher power loads. On a scale from 0 to 10 where 0 is silent and 10 is the loudest, I would subjectively rate the V850 SFX Gold 850W at 3.5/10 acoustically under nominal loads, because the fan does spin up a bit more under heavier loads.
Cooler Master provided this product to APH Networks for the purpose of evaluation.
I always enjoy looking at SFX power supplies because of the pure power density of these sorts of units. The Cooler Master V850 SFX Gold 850W is another entrant into this market with a solid ten-year warranty and 80 Plus Gold rating. Our affiliates and third-party review websites have shown the Cooler Master V850 SFX Gold 850W offers great efficiency, voltage regulation, and ripple control. However, I think this Gospower-made unit could be improved in terms of internal component selection, and increasing the length of the peripheral cables will be good for compatibility in slightly larger cases. The noise output is a bit more noticeable, but also understandable, considering the smaller size. Looking at the retail market, the Cooler Master V850 SFX Gold 850W was supposed to be available for $140 USD. However, due to the current global situation, the current prices are about 50% higher than MSRP. At launch price, this is still a pretty impressive little unit, but it is unfortunate we have to contest with prices that are higher than it should be.
Page Index
1. Introduction, Packaging, Specifications
2. Physical Look - Outside
3. Physical Look - Inside
4. Minor Tests and Conclusion
