SAMA P1000 ATX 3.1 PSU Review – 1kW platinum power at a competitive price

1 - Introduction and technical data 2 - Unboxing, asccessory and cables 3 - Teardown, components, fan and protection circuits 4 - Cybenetics methods and equipment 5 - Performance and test results 6 - Operating noise 7 - Efficiency and power consumption 8 - Summary and conclusion

Noise development and interpretation of the diagram

The noise development of the SAMA P1000 is one of the strongest points of this power supply and is accordingly rewarded with a very high LAMBDA rating in the Cybenetics protocol. This diagram shows the sound level distribution at 230 volts as a colored map over the load range and makes it clear at which operating points the fan remains practically inaudible and when a measurable or subjectively perceptible increase in noise sets in. The 12-volt power output up to 1000 watts is shown on the horizontal axis, while the combined power output of the 3.3 and 5-volt secondary lines up to 100 watts is shown vertically. The color coding ranges from red for extremely low values below the measurement noise limit to cyan and yellow for higher levels well above 25 decibels.

The first striking feature is the large red area, which extends from idling to well over 400 watts on the 12-volt rail, with typical secondary line loads. Red here stands for less than 6 decibels above the background noise level of the test laboratory, which corresponds to practically inaudible operation. In this range, the fan is either running at a very low speed or is practically in the semi-passive range from an acoustic point of view, even when it is rotating. In practice, this means that typical everyday loads of a gaming or workstation system, i.e. around 100 to 300 watts on 12 volts and moderately loaded 3.3/5 volt rails, are barely audible. The power supply disappears into the noise mix of the system and is completely masked by the case fans or graphics card.

In the transition range between around 450 and 600 watts of 12-volt power, the coloration gradually changes from red to blue and green. Blue and green stand for levels roughly between 10 and 20 decibels above the noise level of the measurement room. This is a range in which the fan works measurably, but is still perceived as very quiet in a closed housing. Especially in the typical gaming scenario with short-term power peaks and an average consumption in the range of 400 to 600 watts, the power supply unit remains pleasantly restrained for the vast majority of users. The card also shows that the secondary load only has a moderate influence on the noise development, meaning that even high 3.3 and 5 volt loads within realistic limits do not lead to abrupt jumps in the noise level.

The fan only becomes more aggressive at significantly higher loads: from around 650 to 700 watts of 12-volt power, the coloration shifts to yellow and violet, which means levels of around 20 to 30 decibels. This is audible, but still comparatively moderate for a power supply in this performance class, especially since such loads only occur in everyday life in very powerful systems with permanent full utilization. For typical gaming workloads, these ranges tend to be exceptional conditions, for example in synthetic stress tests or with heavily overclocked multi-GPU or high-core CPU configurations.

In the upper third of the power range, i.e. above around 800 to 900 watts, the purple and yellow bands finally appear, occasionally accompanied by turquoise areas, which indicate levels above around 30 decibels. This is acoustically quite present, but for a power supply unit that is approaching its maximum power output, it is absolutely within limits and, in direct comparison with other 1000 watt models, rather on the quieter side. The decisive factor here is that there are no sharp jumps or islands with significantly higher levels, but rather a relatively even, comprehensible increase in volume with the load. This speaks for a well-tuned fan curve that does not react frantically, but continuously adjusts the speed with the thermal load.

The diagram thus shows that the SAMA P1000 operates extremely quietly across the entire practical load range and only enters a range where the fan is clearly audible when the load is permanently high. This is a very pleasing characteristic for the intended target group, i.e. high-performance gaming PCs and workstations in the upper mid-range to high-end segment. In typical gaming situations or productive workloads, the power supply unit remains acoustically inconspicuous so that other components dominate the noise profile. Only those who regularly operate the power supply close to its maximum load should expect a clearly perceptible, but still controlled fan noise. All in all, the noise development is clearly one of the strengths of the SAMA P1000 and fits in very well with the overall efficient and thermally solid platform.

Measurement methods in detail

Cybenetics uses a clearly defined, reproducible method to determine the noise development of a power supply unit. Measurements are taken in a controlled environment in which the power supply unit is operated over more than 1450 different load combinations. This large number of measuring points is a significant difference to conventional tests, which usually only evaluate a few fixed load conditions. This results in a complete acoustic load profile that reflects the entire operating reality and does not just pick out individual scenarios.

The evaluation is carried out in the form of the so-called LAMBDA classes. These range from well below 20 dBA for very quiet power supply units to ratings for devices that are clearly audible or even disturbing during operation. The classification classifies the average noise level determined across all measured load points. This means that the focus is not just on a peak value, but on the actual overall average volume that can be expected in everyday use.

Cybenetics measures the volume directly in front of the device, uses calibrated microphones and keeps the environment acoustically constant so that external influences are excluded. The precision of the measurements allows for fine differentiation, which is clearly shown by the individual color segments in the noise diagrams. Each color represents a defined dBA range and illustrates the combinations of 12-volt load and sideline load at which the fan adjusts its speed.