be quiet! System Power 10 550W

[testman78]

Introduction

be quiet! released the updated System Power 10 series that consists of five non-modular models with capacities ranging from 450W to 850W. Today, we're looking at the 550W implementation to see where it stands in the competitive mainstream market. The be quiet! System Power 10 PSUs are actually one of the firm's more price conscious components families. They are without exception 80Plus Bronze certified except 850W model which is Gold. These are mainstream units, suitable for cost-effective systems with low power requirements where efficiency isn't priority one. In our opinion efficiency, which in a power supply represents the ratio of the output power divided by the input power, is of immense importance. However, many users put their budget first so there is great demand for affordable, but less efficient units like the System Power 10 550W.



be quiet! likes to emphasize the level of protection and safety that System Power 10s offer unlike many other budget power supplies: they are equipped with protections against over-current, over- and under-voltage, short-circuit, over-temperature and power over-current protection.




Packaging & Contents

At the front of the box there is a photo of the power supply along with the model number and the capacity.



At the rear you will find the power specifications table and a number of badges, depicting the various certifications that this product meets.



Only a bubble-wrap protects the unit inside the box. It would be far better if packing foam sheets were also used.



You will only find a user's manual, power cable and four fixing bolts, besides the power supply, in the box. be quiet! tried to keep the cost as low as possible, and this means no zip ties or Velcro straps in the bundle.






A Closer Look Outside

The external design is plain, as expected in a budget-oriented product – and the finish is semi-matte so it doesn't attract fingerprints like flies. Usually matte coatings are also more scratch-resistant compared with a glossy finish.



There is a plastic grommet around the cable exit hole, protecting the cables from the cases edges. Speaking of the cables, the main ATX is fully sleeved back into the housing while the rest are flat. The dimensions are small (140 x 150 x 86 mm) and the cooling fan is not installed in the exact center – which looks odd. Most likely it provides better airflow to the areas of interest as it is.



At the front side the power switch is installed right next to the AC receptacle. The typical honeycomb-style exhaust grille is used here. The be quiet! logo is stamped onto one of the sides.



On the other is a large power specifications label.



All cables are fixed and long enough, so there won't be compatibility problems with up to mid-tower chassis. There is one EPS connector along with two PCIe ones. The number of peripheral connectors is adequate for a budget PSU, while the distance between those connectors is small. Ideally, it should be 150mm because several system components that use them (e.g. case fans), are not close to each other.









A Closer Look Inside

As expected, we opened up the be quiet! System Power 10 550W power supply to take a closer look at what is going on inside. Opening up this power supply will void your five-year warranty, as the warranty seal covers one of the chassis screws. For your benefit, we voided our warranty on this unit, so you do not need to. When we take the hood off the power supply, we encounter the same 120mm fan as on the previous generation. It is a Yate Loon D12SM-12 with a sleeve bearing that is controlled on the basis of the temperature. It uses a sleeve bearing. We would like to see a rifle bearing used, instead. It measures 120mm across and it is controlled by a highly relaxed speed profile.



It is a traditional design as the demands are not that high to achieve 80 Plus Bronze certification. The secondary side is using passive rectification and a group regulation system for rectification of the minor rails.



With closer examination in the circuit, after requisite DC filtration lies the circuit of active power factor correction, for why this power supply differentiates itself from other entry-level budget supplies, which normally are not equipped with this feature. This feature improves the power factor which gets disturbed due to the high switching operation of the magnetics.



Close by, on the primary side, there is a single Elite capacitor rated at 330uF at 400V. It has a temperature rating of 85c. This is a Chinese brand primary capacitor with an 85 Celsius temperature rating, as opposed to Japanese capacitor with the higher 105c temperature rating found in higher end PSUs. Other major electrolytic capacitors around this board are Elite branded capacitors, which is another Chinese manufacturer.



The filtering capacitors are provided also by Elite, so they are of decent quality. Actually Elite caps are considered the best choice for budget platforms, offering good reliability and performance at a good price. Some polymer caps are also used, with two of them installed on the board that hosts the DC-DC converters.



The unit's main transformer, which besides lowering the voltage also provides electrical isolation between the primary and the secondary sides.



The NTC thermistor which is responsible for protection against large inrush currents. It isn't supported by a bypass relay, unfortunately.



Lastly, comes the secondary stage of the supply that accounts for the stabilized, rectified and filtered DC voltage supply, additionally also providing a feedback to the primary side to control the controller parameters.




Instrumentation used


Below we report the instrumentation used in the test phase for the Deepcool PQ850M.



PowerKiller 2.0. Test bench designed for power supplies up to 2185W.
Stingray DS1M12 USB Oscilloscope
PCE-PA 6000 Wattmeter
Range 1W ~ 6kW
Accuracy ± 1.5%
Multimeters
3 x HT81
1 x ABB Metrawatt M2004
1 x Eldes ELD9102
1 x Kyoritsu Kew Model 2001
1 x EDI T053
Multi-Channel Datalogging Digital Thermometer PCE-T 1200
Center 325 sound level meter


Voltage Regulation

The voltage regulation tests are carried out by connecting all the electrical lines to our PowerKiller and simulating the behavior of the power supply with loads comparable to those of a real location.
+3,3 volt
Average voltage 3.366 volt
Deviation from the ideal value (3,33 volt) = +1.09%



+5V
Average voltage 5.168 volt
Deviation from the ideal value (5,0 volt) = +3.36%



+12,0 volt
Average voltage 12.228 volt
Deviation from the ideal value (12,0 volt) = +1.90%



The linear load simulation also testifies to be quiet's excellent work in designing the System Power 10 550W.


Efficiency



The 80Plus Bronze certification achieved by the be quiet! System Power 10 550W is well deserved, even tight. From our surveys, the sample in question has far exceeded the limits imposed by exceeding 88% efficiency at 50% of the nominal load. We are in the presence of excellent values, certainly lower than those achievable by the Gold models which, however, cost on average more than double.


Ripple

Let's continue our dynamic analysis with the power up test. The voltages, graphed thanks to the oscilloscope, grow with a regular trend characterized by a saddle point in the initial part, but almost without peaks. The rise time stands at 10 ms while the power supply becomes operational in 340 ms.





The no-load voltages show a strong sinusoidal component at the mains frequency, a sign that the primary filtering system is unable to completely eliminate the fluctuations of the input voltage. However, the values remain within the norm.





Arriving at full load, the ripple on the voltage varies both in frequency and in amplitude. The first undergoes a doubling on the main frequency equal to 100Hz, ie that of the signal rectified by the input rectifier bridge and is enriched by the high frequency components introduced by the switching transistor (80KHz). The maximum peak-to-peak value reaches 136 mV, almost double, but still acceptable.




On the 5V line the mains frequency disappears and is completely supplanted by the PWM one. The peak-to-peak value is reduced thanks to the introduction of the load which allows the output filter to perform its duty in the best possible way.




Situation similar to what has been seen for 5V occurs on the 3.3V line, however the ripple does not reduce and remains close to the value detected when empty.




The dynamic test conducted on the be quiet! System Power 10 550W can be considered satisfactory: we are not facing record values, but given the range to which it belongs and the purposes of the product it is objectively difficult to ask for more.


Cross Load

Line +3,3 volt





Maximum Vdrop 0.16 volt (4.67%)

Line +5,0 volt





Maximum Vdrop 0.18 volt (3.46%)

Line +12,0 volt





Maximum Vdrop 0.23 volt (1.86%)

be quiet's System Power 10 550W performed very well, the voltages remain perfectly normal even at the maximum load expected for the voltages of interest. The relatively small deviations settle below 5%. The best result is marked by the 12V line, while the lower voltages, while showing clearly smaller absolute differences, slightly lose the percentage comparison. This result, however, should not worry as in real conditions of use it will be difficult to reach loads of this type and, moreover, it must be considered that part of the Vdrop is due to the ohmic drop along the cables, present in fewer numbers than those for i 12V.


OverLoad

Pushing the PSU above its rated limits generates an efficiency level of around 82.9%. This is not a viable ‘real world’ situation, but its interesting nonetheless.




Temperature

The fan helps to ensure that rising load demands are met with increased air flow. Temperatures rise to a 12c above ambient intake at full load.




Noise

The fan spins slowly at general load demand, with noise levels rating below 35dBa. Under higher loads, the fan spins up, but it never becomes intrusive– likely to be drown out by even a single case fan.. This is a testament to the quality of the fan.




Final Thoughts

Every time I have to evaluate a budget power supply I can't help but worry that it won't survive our tests. If a unit fails, I have to wait for the company to send a second sample and the failure can damage our test equipment. Thankfully everything rolled smoothly with the System Power 10 550W since it uses a reliable platform. This might be an older design, but it has been upgraded with the addition of a couple of DC-DC converters, which handle the minor rails. Those converters offer good performance in tough scenarios where the load at +12V is the minimum while at 5V is high, and vice versa. Still, the be quiet! System Power 10 550W might be a budget oriented unit but the performance is quite good and in terms of load regulation it managed to impress us. The non-modular cables provide it with a head start of course, since they have lower voltage drops compared to modular ones … especially at high loads. The non-modular cable design might be a deal breaker for many of you, since today the majority of power supplies are equipped with fully modular cables. Nevertheless, in a budget unit the first thing that usually has to go are the modular cables – which is acceptable if the performance is high enough. Power aside, the cables are probably another noteworthy highlight of the System Power 10 550W. As the cables are mostly flat, cable management and closing of the motherboard tray side panel is guaranteed to be much easier to deal with as compared to the traditional bundled sleeve design. This is especially useful for PC cases with tempered glass panels, reducing the chance of shattering due to excessive pressure caused by the crumpled-up cables at the back panels. The unit also uses good components, including Elite caps, considering its price tag. The only changes that I would like to see are the bulk cap, which ideally should be rated at 105°C and a rifle bearing fan used instead of a sleeve bearing one. Those two changes would affect this unit's price but not significantly, while at the same time, would highly increase its reliability. The cherry on the cake is the ultra quiet operation, something that it is really difficult to find at this price and efficiency range. The lower the efficiency the higher the energy losses so the cooling system has more work to do, and in the majority of cases this means increased airflow – so noise emissions can get higher.



Although personally I would avoid using a lower than 80 PLUS Gold, there's a huge crowd out there for budget power supplies. For those consumers the be quiet! System Power 10 line, including of course the 550W, is a very good choice, especially for the building of a silent office PC. Just be prepared to live without modular cables. The Be quiet! System Power 10 power supplies are just as cheap as their predecessors, but one step more efficient. Perhaps even more important is that they provide stable power to the rest of your components and are equipped with all desirable protections against, for example, overload and short circuit. We have seen this differently with other cheap power supplies. The be quiet! System Power 10 550W is a very quiet power supply that performs at a high level considering the asking price (50€). If you are working with a tight budget then the System Power 10 550W is definitely worth considering. All models come with a 5-year manufacturer's guarantee.