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Efficiency, Temperature & Noise
Efficiency
Our efficiency testing procedure is detailed here.
Using results from the previous page, we plotted a chart showing the TPG-850AH3FSGR’s efficiency at low loads, and loads from 10 to 110 percent of its maximum-rated capacity.
Under normal loads, this PSU's efficiency is among the highest. It could be better with light loads, though.
Efficiency At Low Loads
In the following tests, we measure the TPG-850AH3FSGR's efficiency at loads significantly lower than 10 percent of its maximum capacity (the lowest load the 80 PLUS standard measures). The loads we dial are 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 | PSU Noise | PF/AC Volts |
|---|---|---|---|---|---|---|---|---|---|
| 1 | 1.192A | 0.495A | 0.474A | 0.198A | 19.626 | 59.480% | 0 RPM | <6.0 dB(A) | 0.878 |
| 12.178V | 5.062V | 3.382V | 5.053V | 32.996 | 115.05V | ||||
| 2 | 2.449A | 0.990A | 0.979A | 0.397A | 40.023 | 80.075% | 0 RPM | <6.0 dB(A) | 0.876 |
| 12.131V | 5.058V | 3.377V | 5.039V | 49.982 | 115.05V | ||||
| 3 | 3.641A | 1.484A | 1.454A | 5.026A | 59.514 | 84.717% | 377 RPM | 6.8 dB(A) | 0.921 |
| 12.115V | 5.053V | 3.373V | 5.026V | 70.250 | 115.05V | ||||
| 4 | 4.899A | 1.983A | 1.961A | 0.798A | 79.938 | 86.625% | 388 RPM | 6.8 dB(A) | 0.926 |
| 12.109V | 5.049V | 3.368V | 5.012V | 92.280 | 115.05V |
With 20W load, the registered efficiency is very low. It should be closer to 70%. Efficiency gets a large boost in the other three tests, exceeding the 80% mark. That large efficiency gap between our 20W and 40W load tests looks odd.
5VSB Efficiency
The ATX specification (revision 1.4), along with CEC, ErP Lot 3 2014 and ErP Lot 6 2010/2013, states that 5VSB standby supply efficiency should be as high as possible, recommending 75 percent or higher with 550mA, 1A, and 1.5A of load. The PSU should also achieve higher than 75% efficiency at 5VSB under full load, or with 3A if its max current output on this rail is higher than 3A.
We take six measurements: one each at 100, 250, 550, 1000, and 1500mA, and one with the full load the 5VSB rail can handle.
| Test # | 5VSB | DC/AC (Watts) | Efficiency | PF/AC Volts |
|---|---|---|---|---|
| 1 | 0.100A | 0.510 | 73.171% | 0.053 |
| 5.090V | 0.697 | 115.37V | ||
| 2 | 0.250A | 1.271 | 76.705% | 0.118 |
| 5.083V | 1.657 | 115.37V | ||
| 3 | 0.550A | 2.789 | 79.731% | 0.211 |
| 5.069V | 3.498 | 115.37V | ||
| 4 | 1.000A | 5.050 | 80.261% | 0.290 |
| 5.049V | 6.292 | 115.37V | ||
| 5 | 1.500A | 7.540 | 80.213% | 0.335 |
| 5.026V | 9.400 | 115.36V | ||
| 6 | 3.000A | 14.852 | 77.516% | 0.395 |
| 4.950V | 19.160 | 115.35V |
The 5VSB rail's load regulation might be loose, but its efficiency levels are high at least.
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 | 12.211V | 5.064V | 3.385V | 5.063V | 8.977 | 0.631 |
| 115.1V | ||||||
| Standby | 0.090 | 0.007 | ||||
| 115.1V |
Vampire power is higher on the TPG-850AH3FSGR than most of its competition. We expected a lower reading, especially with 230V input.
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 38°C (100.4°F) to 47°C (116.6°F) ambient temperature.
The next chart shows the cooling fan's speed (again, in RPM) and output noise. We measure acoustics from one meter away, inside a hemi-anechoic chamber. Background noise inside the chamber is below 6 dB(A) during testing (it's actually much lower, but our sound meter’s microphone hits its floor), and the results are obtained with the PSU operating at 38°C (100.4°F) to 47°C (116.6°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 is between 30°C (86°F) to 32°C (89.6°F).
The passive mode doesn't last long, and if you push the minor rails it gets even shorter.
Overall, Thermaltake's fan profile is loose. As a result, with up to 550W load at +12V, the PSU's noise doesn't exceed 20 dB(A). Worst-case, you're looking at an output noise measurement close to 36 dB(A).
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