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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 RX-700AT's efficiency at low loads, and loads from 10 to 110 percent of the PSU's maximum-rated capacity.
Under normal loads, the RX-700AT easily takes first place, leaving the highly efficient EVGA 650 P2 behind. However, the situation turns under light loads and Raidmax's PSU falls away from the top of the graph. Because this is a Titanium-rated product, we expected it to perform well regardless of load level.
Efficiency At Low Loads
In the following tests, we measure the efficiency of Raidmax's RX-700AT 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 | 1.194A | 0.491A | 0.476A | 0.194A | 19.62 | 69.80% | 580 | 22.0 dB(A) | 0.808 |
| 12.196V | 5.069V | 3.339V | 5.066V | 28.11 | 115.1V | ||||
| 2 | 2.418A | 0.978A | 0.986A | 0.391A | 39.72 | 82.75% | 580 | 22.0 dB(A) | 0.875 |
| 12.193V | 5.072V | 3.340V | 5.068V | 48.00 | 115.1V | ||||
| 3 | 3.637A | 1.466A | 1.495A | 5.067A | 59.80 | 87.31% | 580 | 22.0 dB(A) | 0.912 |
| 12.204V | 5.071V | 3.339V | 5.067V | 68.49 | 115.1V | ||||
| 4 | 4.851A | 1.973A | 1.975A | 0.785A | 79.76 | 91.18% | 580 | 22.0 dB(A) | 0.932 |
| 12.202V | 5.070V | 3.338V | 5.064V | 87.48 | 115.1V |
With 20W load, efficiency drops below 70 percent. That significantly affects the average efficiency score under light loads. Our results are much better in the other three tests, with efficiency exceeding 91 percent under 80W of load. In addition, the fan is inaudible.
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 will 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 | 0.50 | 72.46% | 0.042 |
| 4.992V | 0.69 | 115.1V | ||
| 2 | 0.251A | 1.25 | 77.16% | 0.095 |
| 4.990V | 1.62 | 115.1V | ||
| 3 | 1.002A | 4.99 | 82.21% | 0.265 |
| 4.978V | 6.07 | 115.1V | ||
| 4 | 2.502A | 12.39 | 80.30% | 0.380 |
| 4.952V | 15.43 | 115.1V |
Besides maintaining super tight load regulation, the 5VSB rail is also highly efficient.
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 it's in standby mode (without any load, at 5VSB).
| Mode | 12V | 5V | 3.3V | 5VSB | Watts | PF/AC Volts |
|---|---|---|---|---|---|---|
| Idle | 12.219V | 5.066V | 3.339V | 5.066V | 5.48 | 0.299 |
| 115.1V | ||||||
| Standby | 0.07 | 0.004 | ||||
| 115.1V |
Vampire power is very low, and the RX-700AT easily meets the ErP Lot6 2013 directive.
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 34 °C (93.2 °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 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 34 °C (93.2 °F) to 47 °C (116.6 °F) ambient temperature.
The following graph illustrates the fan's output noise over the PSU's entire operating range. The same conditions of the above graph apply to our measurements, though the ambient temperature was between at 28 °C (82.4 °F) to 30 °C (86 °F).
With ambient temperatures under 30 °C, the PSU features silent operation. Up to around 415W load, the fan's noise is close to 22 dB(A) and it takes more than 600W for the noise to exceed 40 dB(A). Under high loads the fan profile could be more relaxed without negatively affecting this unit's reliability.
