Cooler Master has already reworked its entry-level series “B” long ago and has introduced an improved version on the market with the “Ver.2”. The new version has been adapted to current energy saving guidelines, and Cooler Master has now also donated a complete protective circuit pack to the entry level, which of course makes these power supplies interesting in view of the favorable price. Whether the B400 Ver.2 is also currently a recommendation in the entry segment, we have looked at ourselves.
The Cooler Master B Series is the entry level, which is primarily intended for simple home or office computers. Accordingly, performance and equipment are somewhat lower, also to extras such as modular cable management is to be dispensed with. The models of the B series can, of course, offer a comparatively low price. Cooler Master B400 Ver.2 tested here is at a market price of just under 40 euros.
The B Series includes four 400 to 700-watt models, all of which are 80PLUS-certified. The B Ver.2 have reached “80PLUS 230V EU”, ie the basic level of the scale, which at 85% load requires an efficiency of 85%.
The Cooler Master B400 Ver.2 is delivered in a printed box, which contains the essential information on the power supply pack enclosed in the air-cushioned foil.
The scope of delivery of the Cooler Master B400 Ver.2 is very clear. In addition to the mains cable and the montage screws, there are also two multilingual small leaflets as a “manual”. After all, the technical data, the connector assignments and the guarantee information are to be found on these.
The Cooler Master B400 Ver.2 offers no surprises in terms of optics and has the usual look based on a dark steel body painted in dark anthracite.
The housing has the standard dimensions of an ATX power supply with a length of 140 mm. The usual “radial” version made of black wire mesh is used as a fan grille, with the difference that the fan grille is not positioned as usual on the lid but between the cover and the fan, which makes the Cooler Master B400 Ver.2 a small special feature In the optics for itself.
The Cooler Master B400 Ver.2 is equipped with fixed connection cables, but this is not a problem in this price class normal and in view of the still low Watt class and the correspondingly smaller number of connection possibilities. Accordingly, the inside of the power supply is also unspectacular.
According to the feature list, the Cooler Master B400 Ver.2 offers quite decent performance. The B400 Ver.2 is certified according to 80PLUS in the “230V EU” variant, which means that it should achieve an efficiency of 80% at low and full load, and at half load 85%. The Cooler Master B400 Ver.2 is not a power supply with wide range input, but only on 230V networks.
The Cooler Master B400 Ver.2 is also set up according to the class. On the auxiliary voltages up to 120 watts are available combined, which divide up to 20 Ampere to 3.3 Volt and 5 Volt. The 12-volt side is designed as a single-rail design and is nominally loadable with up to 30 amperes, which corresponds to a computational power of 360 watts. For computers with a maximum of a midrange graphics card – there is also only one PCI Express port available – this is certainly sufficient or simply appropriate.
The Cooler Master B400 Ver.2 should also bring several protection circuits. For example, protection circuits for overvoltage (OVP), overload (OPP), overloading of individual rails (OCP) and short circuit (SCP) should be provided for the B400 Ver.2. Cooler Master wants to have integrated a protection against overheating (OTP).
We tested the overload protectors as usual, first on the secondary voltages. It was shown that a load of 30 amperes was sufficient for 3.3 volts and 5 volts to trigger a switch-off of the power supply. Similarly, the 12V side showed a load of about 40 amperes to trigger the protection circuit. Very nice to see that Coolermaster also has a “40 Euro power supply” the important basic protection circuits donated, which is unfortunately much more expensive power supply is missing.
A quick look at the inner life shows that the Cooler Master B400 Ver.2 uses a platform of the order finder Channelwell (CWT). This is based on a group-regulated design, without DC-DC technology and with a classic double-forward topology. The relatively cheap price of the B400 ver.2 is probably the choice of capacitors owed. Primary is an Elko with the brand name “Elite” with 270 uF capacity (400V, 85 ° C GM series) voltage resistance, which is produced by the Taiwanese company Chinsan Electronics. On the secondary side are mainly Elkos of CapXon and also some Su’scon in the employment.
The Cooler Master B400 Ver.2 does not appear as a silent power supply, but is at least advertised with a quiet 120 mm fan. Cooler Master also provides the use of a “Hydrodynamic Bearing” fan and a fan control with intelligent speed control.
The Cooler Master B400 Ver.2 is equipped with an active control 120-mm fan of the Yate Loon brand, which has the model number D12SM-12 (link to the manufacturer’s side) and can reach a maximum of 1,650 rpm. The fan is given by Yate Loon as a model with sliding bearing, but a small dripping oil in a sliding bearing misses the whole yes also the necessary portion “hydrodynamics”.
In operation, the Cooler Master B400 Ver.2 left a good overall impression. The fan starts at low speed with a speed of almost 900 rpm, which he could maintain in our test operation up to 80 percent load. From the impression was the fan thereby still of a pleasant volume, so quite quietly. We could only notice coil spinning / chirping at the load point of 5%, which is not practical and is still far outside the reasonable operating range of a simpler power supply. The speed was then increased above 80% load and reached a value of 1,250 rpm at the full load operating point after some time. The fan produced a low air noise, but the bearing noise was quite noticeable. The Cooler Master B400 Ver.2 is therefore not a silent power supply, but offers a range for its application – simpler, air-cooled computer – a pleasantly low volume.
In terms of connectivity the Cooler Master B400 Ver.2 is usable. With an 8 (4 + 4) pin-eps connector, six SATA and three Molex connectors, it offers the class-like variety. In terms of class, the single PCI Express connector corresponds to the standard.
Cooler Master equips the B400 Ver.2 with fixed connection cables, whose length can be described as quite generous. The single strands of the ATX main cable are combined with a black network sleeve, just like the wires of the 8-pin CPU and the PCI Express cable are bundled with a sleeve. All other cables consist of colored single strands which are held together only in some places by cable ties. In the relationship the Cooler Master B400 Ver.2 with high-quality models in terms of optics and handling of course can not keep up, but for this class this is already a good equipment.
Since the introduction of the 80PLUS program almost eight years ago, the power factor efficiency has become increasingly central. The system, which is easy to understand for customers, behind 80PLUS, also enables an efficient marketing of the quality factor efficiency. Since 80PLUS’s certification system is not necessarily considered to be tamper-proof, and 80PLUS should not be overstated, the overall system is more oriented towards the interests of the companies than the end users. In any case, it must not be understood as a quality seal for the entire power supply, since efficiency is only one feature of many that is relevant to a good power supply. Before buying a power supply, you should therefore continue to be informed of various objective sources.
Regardless of 80PLUS: The nice thing about power supply efficiency is that the customer can now find several reasons for buying a particularly good power supply. He can use it to save energy costs, he can calm down his green conscience by using the CO2 power that has been saved, but probably the most important reason is that a high efficiency can also be believed in the latest and best technology. Therefore, a look at the quality of the output voltages is still important, because a good power supply should work efficiently AND stable.
Since our test station allows not only the power consumption from the power grid but also the power delivered to the (imaginary) PC, we can also make quantitative comparisons of the power supplies tested. In this case, we determine the efficiency over the load range of the power supply itself and then to a practical comparison to three points which are the same for all power supply units.
In the meantime, the efficiency measurements are now being started at a very low five percent load, which corresponds to just 20 watts of output. Because of this very low load and the platform, which is also not necessarily optimized for maximum efficiency, the measured efficiency of the Cooler Master B400 Ver.2 is sufficient at 70.4%. At a ten percent load, viable 77.2% is already reached.
With a load of 20%, our test candidate slowly reaches its actual working range. The efficiency is then already 84%. In the range of 40 to 60% utilization, the power supplies usually reach their maximum efficiency, as does the 400W strong Cooler Master B400 Ver.2 with 86.5% at 40% load. It is striking that even at 30% load, a good 86.2% is reached, that is, The Coolermaster can reach an efficiency of 86% in the range of 30 to 60% load. After the peak at 40%, the efficiency curve then drops again slowly and still reaches a value of 83.1% at full load.
The normal test with the conversion of our voltage source to 115 volts, of course, we do not need to make a 230V-only power supply since we already have our measurements – which are not exactly comparable to 80PLUS. For 80PLUS 230V EU, efficiency values of at least 82% / 85% / 82% are required at the three important load points (20% / 50% / 100%). The Cooler Master B400 Ver.2 reaches 839% / 86.4% / 83.1%. 80PLUS Bronze 230V EU (85% / 88% / 85%) is not enough at any of the three measuring points.
Also interesting is the direct comparison at three fixed load points, since here the power supply units can be directly compared to one another, as if they are used in the same computer. The first point with 90-watt power consumption corresponds to older office PCs or a modern mid-class system in idle. The Cooler Master B400 Ver.2 achieves a comparatively good efficiency with 85.5%, which makes it well suited to other selected entry-level models and some higher-rated 80PLUS bronze models.
At somewhat higher values, in this case 250-watt power consumption of the system, the Cooler Master B400 Ver.2 drops somewhat, since the usually stronger comparative power supplies arrived here at a more optimal working point. At 85.9%, however, it is still at a relative strike distance. At the third measuring point, at 500 watts of power consumption, which means that the Cooler Master B400 Ver.2 is already far in the overload range, it has another piece on e.g. The domestic and only slightly more expensive Coolermaster G450M lost, but for the sake of completeness.
The efficiency is not one of the strengths of the Cooler Master B400 Ver.2, but it can be used for a power supply with 80PLUS standard efficiency. Particularly at low load, it offers a modern and efficient efficiency
The quality of the output voltages is one of the most important features of a power supply, actually even more important than its efficiency. If a power supply is not stable or supplies fluctuating voltages, the function of the computer can be impaired. We therefore look at how the voltages under load change and whether they remain within the tolerance range defined by the ATX Design Guide. This allows deviations of +/- 5% from the nominal voltage, the value range of the diagrams corresponds exactly to this tolerance range.
We also look at the quality of the output voltages per oscilloscope in detail. The so-called ripple / noise voltages are high-frequency alternating voltages which are impressed on the actual output DC voltage. They arise due to the operation of switching network elements and are filtered out to a greater or lesser degree, depending on the quality of the network signal or its output filter. The ATX Design Guide stipulates that 12 V values of 120 mV (pp, “peak-to-peak”), at 3.3 volts and 5 volts 50 mV (pp) may occur.
When it comes to voltage regulation under evenly distributed load, the Coolermaster B400 Rev.2 can show a good performance for this class. In particular, this is because a group-regulated design is used in which – unlike DC-DC power supplies – the control of the three main output voltages is interdependent. The 3.3V and 5V less commonly used nowadays fluctuate by 1.9% and 2.9% respectively, which means they are safely within tolerance. The position in the upper half of the tolerance field is also good.
On the 12V side, the fluctuation width in the range of ten percent load to full load is very low 0.6%. For a beginner’s share of the 40 euro class, therefore, a good overall performance.
The position at the ripple / noise voltages looks very good: Here the Coolermaster B400 Rev.2 can be used with max. 14 or 9 mV (pp) to 3.3 volts and 5 volts show surprisingly good values. The 12V side also has a very high level of 11 mV (pp), which is rarely achieved even in higher classes.
Coolermaster B400 Rev.2 can give a comparatively good figure in the quality of the output voltages. The voltages are well balanced for this class and the low ripple / noise voltages are even very good.
Cooler Master has introduced a successful series of starter sets with the second version of the B series. Cooler Master B400 Ver.2 was able to show a very solid, in some areas even good performance.
As an entry-level power supply with 400 watts of power, which are also fully available as with “Billignetzteile / Chinaböllern”, the B400 Ver.2 can not score with comfort features like cable management or numerous connections. The latter, however, correspond to the performance class and also to the pleasingly low operating volume, the B400 Ver.2 likes to please. Rather, only average is the efficiency of the 80PLUS “standard” (230V EU) certified power supply, but with just under 86.5% at the top, it still offers a modern high efficiency.
Very good, we at the B400 Ver.2 liked that it has overload protection circuits. Even a protective circuit against overheating should be on board. Its output voltages show an overall neat voltage control, which makes a stable impression. On the other hand, the very low ripple / noise voltages are very good.
The Coolermaster B400 Ver.2 can meet all the points that we expect with a good power supply in the favorable entry-level class with the quiet operation, the existing protection circuits, the very solid output voltages and a practical efficiency.