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, initial consumption was 8.0W as measured by our wall meter -- indicating the basic load-free power consumption of the power supply is excellent. Independent reviews from websites with professional load testing equipment showed the SilverStone SFX SX650-G 650W delivered excellent efficiency, voltage regulation, and ripple across all rails. This is an 80 Plus Gold certified power supply unit.
Voltages with minimal load are generally accurate, which is a basic requirement of power supplies out of the box. In this situation all are well within 4%. The PG (Power Good) delay seems to be well within its rated range and general power supply standard at 260ms.
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 these components all measure power, they are not the same as each other. 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. Under nominal loads, the power factor value of the SilverStone SFX SX650-G 650W was at 0.97, indicating that the active PFC function is working well.
Unlike some recent power supplies, this unit has an always-on fan, no matter what wattage it is delivering. According to our APH Networks scale, where 0 is silent and 10 is the loudest, I would rate the SilverStone SFX SX650-G 650W at 3.5/10 acoustically under nominal loads. Despite its smaller size fan and higher operating speeds, I never really found the noise from the power supply to be distracting, and the unit stayed quiet in our testing circumstances.
SilverStone provided this product to APH Networks for the purpose of evaluation.
The SilverStone SFX SX650-G 650W is another excellent SFX unit from SilverStone with High Power as the OEM. According to our affiliates, the SilverStone SFX SX650-G 650W provided very good quality voltage regulation, ripple control, and standby efficiency. Retailing for about $135 USD at press time, the SX650-G 650W is a great option, though there are a couple things I would look at. At this price, some component choices, such as the primary capacitor, could be improved upon, as well as increasing the overall length of the warranty to at least five years. This is the densest PSU available in the market today, and if you are looking to squeeze every last watt out of the SFX form factor, the SilverStone SFX SX650-G 650W is an excellent buy.
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Page Index
1. Introduction, Packaging, Specifications
2. Physical Look - Outside
3. Physical Look - Inside
4. Minor Tests and Conclusion
