Efficiency, Temperature & Noise
Efficiency
Our efficiency testing procedure is detailed here
Using the previous page's results, we plotted a chart showing the MasterWatt Maker 1200 MIJ's efficiency at low loads, and loads from 10 to 110 percent of its maximum-rated capacity.
Again, this is a very efficient PSU. Even under light loads, it exceeds the 80% mark.
Efficiency At Low Loads
In the following tests, we measure the MasterWatt Maker 1200 MIJ's efficiency at loads significantly lower than 10 percent of its maximum capacity (the lowest load the 80 PLUS standard measures). The loads we dialed were 20, 40, 60, and 80W. This is important for representing when a PC is idle, with power-saving features turned on.
| Test # | 12V | 5V | 3.3V | 5VSB | DC/AC (Watts) | Efficiency | Fan Speed | Fan Noise | PF/AC Volts |
|---|---|---|---|---|---|---|---|---|---|
| 1 | 1.213A | 0.482A | 0.476A | 0.196A | 19.640 | 70.782% | 0 RPM | 0 dB(A) | 0.674 |
| 12.024V | 5.106V | 3.350V | 5.099V | 27.747 | 115.11V | ||||
| 2 | 2.456A | 0.970A | 0.985A | 0.390A | 39.762 | 81.724% | 0 RPM | 0 dB(A) | 0.684 |
| 12.022V | 5.105V | 3.348V | 5.095V | 48.654 | 115.11V | ||||
| 3 | 3.696A | 1.460A | 1.491A | 5.090A | 59.850 | 85.995% | 0 RPM | 0 dB(A) | 0.713 |
| 12.021V | 5.105V | 3.346V | 5.090V | 69.597 | 115.11V | ||||
| 4 | 4.927A | 1.954A | 1.971A | 0.786A | 79.784 | 88.459% | 0 RPM | 0 dB(A) | 0.691 |
| 12.019V | 5.105V | 3.345V | 5.086V | 90.193 | 115.12V |
Under light loads, high-capacity PSUs usually don't achieve high efficiency. That's not the case here, though.
5VSB Efficiency
The ATX specification states that 5VSB standby supply efficiency should be as high as possible, recommending 50 percent or higher efficiency with 100mA of load, 60 percent or higher with 250mA of load, and 70 percent or higher with 1A or more of load.
We take four measurements: one each at 100, 250, and 1000mA, and one with the full load the 5VSB rail can handle.
| Test # | 5VSB | DC/AC (Watts) | Efficiency | PF/AC Volts |
|---|---|---|---|---|
| 1 | 0.101A | 0.516 | 67.628% | 0.050 |
| 5.089V | 0.763 | 115.11V | ||
| 2 | 0.252A | 1.279 | 73.845% | 0.110 |
| 5.082V | 1.732 | 115.11V | ||
| 3 | 1.002A | 5.068 | 75.462% | 0.323 |
| 5.057V | 6.716 | 115.12V | ||
| 4 | 3.501A | 17.440 | 70.593% | 0.504 |
| 4.981V | 24.705 | 115.10V |
The 5VSB rail is one of this product's weak links, according to the poor efficiency levels we observe.
Power Consumption In Idle And Standby
In the table below, you'll find the power consumption and voltage values of all rails (except -12V) when the PSU is idle (powered on, but without any load on its rails), and the power consumption when the PSU is in standby mode (without any load, at 5VSB).
| Mode | 12V | 5V | 3.3V | 5VSB | Watts | PF/AC Volts |
|---|---|---|---|---|---|---|
| Idle | 12.022V | 5.105V | 3.352V | 5.104V | 7.426 | 0.409 |
| 115.1V | ||||||
| Standby | 0.053 | 0.004 | ||||
| 115.1V |
Vampire power is kept incredibly low.
Fan RPM And Delta Temperature
Our mixed noise testing is described in detail here.
The first chart below illustrates the cooling fan's speed (in RPM), and the delta between input and output temperature. The results were obtained at 37°C (98.6°F) to 47°C (116.6°F) ambient temperature.
Unfortunately, it was impossible to take our usual noise measurements because the PSU's fan proved incompatible with our speed control equipment. Apparently, its circuit is different from the MasterWatt 1200's, which didn't give us any trouble.
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