Deepcool Quanta DQ750 750W (Page 4 of 4) | Reports

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 have to be taken into consideration -- of which certain criteria consists 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're not going to try to BS you 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 10W as measured by our wall meter unit -- indicating that the basic load-free power consumption of the power supply is very good. Other units we have seen with the same reading in the past include the Cooler Master V1000 1000W, PC Power & Cooling Silencer Mk III 1200W, Seasonic Platinum 1000W, and OCZ ZX Series 850W. Independent reviews from websites with professional load testing equipment showed the Deepcool Quanta DQ750 750W delivered good efficiency, voltage regulation, and ripple across the board -- right up to its rated wattage. This includes its 80 Plus Gold certification.

Voltages with minimal load are generally accurate, which is a basic requirement of power supplies out of the box. In this situation all are within 2%. The PG (Power Good) delay seems to be well within its rated range and general power supply standard of 320ms.

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 save 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/S. The ideal value is 1.00, and this is where active PFC comes in. A nominal load of 135W (18%) on the Deepcool Quanta DQ750 750W had the power factor at 0.95. As the load increases, the PF should approach 0.99.

The Deepcool Quanta DQ750 750W is fairly quiet power supply, but definitely not the best we have seen. Under regular loads (Less than 300W), the 750W Quanta DQ750 is reasonably low noise. Personally, I found the Yate Loon D14SH-12 is a not as smooth running as I would like it to be, but good placement of internal components contributes to minimal turbulence noise. While this is very subjective, I am quite a picky person on noise, and the loudest component in my entire system are my Noctua fans. On a scale from 0-10 where 0 is silent and 10 is the loudest, I would rate the Deepcool Quanta DQ750 750W to be at 3.0/10 acoustically under nominal loads. The fan is out of the way to approximately 50% of its maximum speed, but it will become exponentially more audible when it kicks in. If you are a silent PC enthusiast, the Deepcool Quanta DQ750 750W is still a respectable choice, but the fan motor's smoothness leaves a bit to be desired.

Deepcool provided this product to APH Networks for the purpose of evaluation.

The Deepcool Quanta DQ750 750W delivers pretty decent performance according to our affiliates with professional load testing equipment, but the hardware selection and build quality definitely leaves some questions on the table with regards to reliability. Carrying an MSRP of about $130 at press time, the Quanta DQ750 is a good looking 80 Plus Gold certified power supply with a blue LED fan (If that is your thing). However, if Deepcool wants to take the game seriously, and become an important player among the competition, this PSU will either need a sizable retail discount, or make some serious improvement to the bill of materials.

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Page Index
1. Introduction, Packaging, Specifications
2. Physical Look - Outside
3. Physical Look - Inside
4. Minor Tests and Conclusion