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 8W as measured by our wall meter unit, indicating that the basic load-free power consumption of the power supply was very good. Independent reviews from websites with professional load testing equipment showed the be quiet! Pure Power 11 FM 1000W delivered very good efficiency, acceptable voltage regulation, and acceptable ripple across all rails. 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 are all within 3%. The PG or Power Good delay is tested at 170ms. This power supply officially supports Alternative Sleep Mode, so it is likely the PSU tester was not fast enough to pick up the true PG signal. The design specifications state it 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 be quiet! Pure Power 11 FM 1000W has active PFC, and the power factor will approach 0.99 with a nominal load.
The be quiet! Pure Power 11 FM 1000W is a very quiet power supply. Under regular loads up to 70%, the 1000W Pure Power 11 FM is barely audible. Personally, I found the BQ QF2-12025-HS fan to be very good, living up to the name of the brand. While this is very subjective, I am quite a picky person on noise. On a scale from 0 to 10 where 0 is silent and 10 is the loudest, I would rate the be quiet! Pure Power 11 FM 1000W to be at 1.5/10 acoustically under nominal loads, because the fan spins really slowly. It is too bad it does not have a fan-stop feature, but this is as close as it gets. The fan is mostly out of the way even when the load increases, but as with all fans, it will become more audible as it spins faster. If you are a silent PC enthusiast, the be quiet! Pure Power 11 FM 1000W is a very respectable choice thanks to the PSU's quiet fan curve profile.
be quiet! provided this product to APH Networks for the purpose of evaluation.
The be quiet! Pure Power 11 FM 1000W is a power supply that mostly lives up its name by delivering reasonably pure power with minimal noise. Do keep in mind that although it looks very similar to the 550W to 750W variants in the lineup, the 850W and 1000W model we are reviewing today are actually totally different PSUs built by HEC rather than CWT. Still, it is compliant with the latest ATX specifications with a short PG time and, according to others with professional load testing equipment, has delivered acceptable performance. There is a reasonably acceptable selection of internal components inside and the rifle bearing fan has a low speed fan profile for generally quiet operation. A 5-year warranty is acceptable for a power supply of this class, but many have moved on to offering 10-year coverage. Drawbacks of the Pure Power 11 FM 750W comes down to a multiple 12V rail design uncommon in modern power supplies of this wattage and not a single Japanese brand capacitor anywhere at all. But for about $160 at press time, the price is very reasonable for an 80 Plus Gold certified 1000W fully modular PSU.
Page Index
1. Introduction, Packaging, Specifications
2. Physical Look - Outside
3. Physical Look - Inside
4. Minor Tests and Conclusion
