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Efficiency, Temperature And Noise
Efficiency
Our efficiency testing procedure is detailed here.
Using the results from the previous page, we plotted a chart showing the TPG-1200D-P's efficiency at low loads, and loads from 10 to 110 percent of its maximum-rated capacity.
This is the first time we've seen a PSU achieving higher efficiency at light loads with 230V compared to 115V. We suspect this has something to do with the APFC's operation. The TPG-1200D-P matches most of the competition in this category under normal loads, and it registers decent efficiency under light loads where FSP's Platinum-rated solution and Super Flower's Titanium-class PSU leave the others far behind.
Efficiency At Low Loads
In the following tests, we measure the efficiency of the TPG-1200D-P 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 (RPM) | Fan Noise | PF/AC Volts |
|---|---|---|---|---|---|---|---|---|---|
| 1 | 1.205A | 0.483A | 0.475A | 0.194A | 19.65 | 64.20% | 840 | 29.9 dB(A) | 0.841 |
| 12.121V | 5.103V | 3.350V | 5.098V | 30.61 | 115.1V | ||||
| 2 | 2.434A | 0.978A | 0.985A | 0.389A | 39.76 | 74.65% | 840 | 29.9 dB(A) | 0.900 |
| 12.118V | 5.101V | 3.347V | 5.093V | 53.26 | 115.1V | ||||
| 3 | 3.663A | 1.466A | 1.495A | 5.086A | 59.83 | 80.31% | 840 | 29.9 dB(A) | 0.934 |
| 12.116V | 5.097V | 3.343V | 5.086V | 74.50 | 115.1V | ||||
| 4 | 4.888A | 1.963A | 1.975A | 0.785A | 79.79 | 83.46% | 840 | 29.9 dB(A) | 0.931 |
| 12.113V | 5.093V | 3.339V | 5.079V | 95.60 | 115.1V |
The fan's noise is low. However, the same goes for efficiency during the first two tests. This is a high-capacity PSU though, so it's naturally out of its comfort zone at such low loads. This is why you shouldn't buy an oversized power supply if your PC's hardware doesn't need one.
DPSApp Screenshots
You'll find screenshots of the DPSApp software below, which we took during the light-load test sessions.
The power-out readings are accurate, but the efficiency results are way off.
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 | 0.102A | 0.50 | 71.43% | 0.045 |
| 4.939V | 0.70 | 115.1V | ||
| 2 | 0.252A | 1.24 | 72.94% | 0.105 |
| 4.933V | 1.70 | 115.1V | ||
| 3 | 1.002A | 4.91 | 82.52% | 0.291 |
| 4.901V | 5.95 | 115.1V | ||
| 4 | 3.002A | 14.45 | 79.44% | 0.479 |
| 4.814V | 18.19 | 115.1V |
The 5VSB rail scores high efficiency readings, as you can see from the table above.
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 | 12.123V | 5.109V | 3.354V | 5.110V | 6.08 | 0.256 |
| 115.1V | ||||||
| Standby | 0.07 | 0.004 | ||||
| 115.1V |
Phantom power is very low, which has a positive effect on the 5VSB rail's efficiency.
Fan RPM, Delta Temperature And Output Noise
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 36 degrees C (96.8 degrees F) to 48 degrees C (118.4 degrees F) ambient temperature.
The next chart shows the cooling fan's speed (again, in RPM) and output noise. We measured acoustics from one meter away, inside a small, custom-made anechoic chamber with internals completely covered in sound-proofing material (be quiet! Noise Absorber kit). Background noise inside the chamber was below 18 dB(A) during testing, and the results were obtained with the PSU operating at 36 degrees C (96.8 degrees F) to 48 degrees C (118.4 degrees F) ambient temperature.
The following graph illustrates the fan's output noise over the PSU's operating range. The same conditions of the above graph apply to our measurements, though the ambient temperature was between at 28 degrees C (82.4 degrees F) to 30 degrees C (86 degrees F).
Up to around 780W, the PSU is fairly quiet for a high-capacity unit. This changes quickly above 900W though, and the fan gets very loud. It doesn't stop there; above 1100W, the fan exceeds 50 dB(A). If you push this PSU hard, invest in some earplugs.
The last graph depicts the fan's speed over the PSU's operating range. The ambient temperature during our measurements was between at 28 degrees C (82.4 degrees F) to 30 degrees C (86 degrees F).
