EVGA SuperNOVA 850 G7 Power Supply Review

To learn more about our PSU tests and methodology, please check out How We Test Power Supply Units. 

Primary Rails And 5VSB Load Regulation

The following charts show the main rails’ voltage values recorded between a range of 40W up to the PSU’s maximum specified load, along with the deviation (in percent). Tight regulation is an important consideration every time we review a power supply because it facilitates constant voltage levels despite varying loads. Tight load regulation also, among other factors, improves the system’s stability, especially under overclocked conditions. At the same time, it applies less stress to the DC-DC converters that many system components utilize.

Load regulation is satisfactory on all rails. 

Hold-Up Time

Put simply; hold-up time is the amount of time that the system can continue to run without shutting down or rebooting during a power interruption.

The hold-up time is long and the power ok signal is accurate. The “PWR OK Inactive to DC Loss Delay” signal could be shorter, though. 

Inrush Current

Inrush current, or switch-on surge, refers to the maximum, instantaneous input current drawn by an electrical device when it is first turned on. A large enough inrush current can cause circuit breakers and fuses to trip. It can also damage switches, relays and bridge rectifiers. As a result, the lower the inrush current of a PSU right as it is turned on, the better.

Inrush current is high with both voltage inputs, 115V and 230V, that we tried. 

Leakage Current

In layman’s terms, leakage current is the unwanted transfer of energy from one circuit to another. In power supplies, it is the current flowing from the primary side to the ground or the chassis, which in the majority of cases is connected to the ground. For measuring leakage current, we use a GW Instek GPT-9904 electrical safety tester instrument.

The leakage current test is conducted at 110% of the DUT’s rated voltage input (so for a 230-240V device, we should conduct the test with 253-264V input). The maximum acceptable limit of a leakage current is 3.5 mA and it is defined by the IEC-60950-1 regulation, ensuring that the current is low and will not harm any person coming in contact with the power supply’s chassis.

Leakage current is low. 

10-110% Load Tests

These tests reveal the PSU’s load regulation and efficiency levels under high ambient temperatures. They also show how the fan speed profile behaves under increased operating temperatures.

The PSU can handle harsh operating conditions, that is, increased loads and temperatures, but don’t expect it to be quiet. 

20-80W Load Tests

In the following tests, we measure the PSU’s efficiency at loads significantly lower than 10% of its maximum capacity (the lowest load the 80 PLUS standard measures). This is important for representing when a PC is idle with power-saving features turned on.

The unit achieves high efficiency under light loads, with minimal noise output because the fan doesn’t spin. 

2% or 10W Load Test

From July 2020, the ATX spec requires 70% and higher efficiency with 115V input. The applied load is only 10W for PSUs with 500W and lower capacities, while for stronger units, we dial 2% of their max-rated capacity.

The PSU exceeds 60% efficiency with a 2% load. It would be nice to measure above 70%, though, in this test scenario. 

Efficiency & Power Factor

Next, we plotted a chart showing the PSU’s efficiency at low loads and loads from 10 to 110% of its maximum rated capacity. The higher a PSU’s efficiency, the less energy goes wasted, leading to a reduced carbon footprint and lower electricity bills. The same goes for Power Factor.

The platform is highly efficient with normal loads, also achieving good results with light loads. The competition is tough at light and super-light loads, so FSP could improve the platform in these sectors. 

5VSB Efficiency

The 5VSB rail is efficient. 

Power Consumption In Idle And Standby

We would like to see below 0.1W vampire power with 230V input. 

Fan RPM, Delta Temperature, And Output Noise

All results are obtained between an ambient temperature of 37 to 47 degrees Celsius (98.6 to 116.6 degrees Fahrenheit).

The fan’s speed is not aggressive considering the test conditions, the tiny and overpopulated PCB, and the high power output. 

The following results were obtained at 30 to 32 degrees Celsius (86 to 89.6 degrees Fahrenheit) ambient temperature.       

Some spots in the PSU’s noise map at normal operating temperatures indicate that the fan speed increased notably to cope with heat build-up. This is why it is preferable to have the fan spinning at all times rather than employing a semi-passive operation mode. With more than 690W, the PSU exceeds 30 dBA; with 20-30W more, it goes over 35 dBA. With a larger PCB, allowing for more airflow between parts, and a 135-140mm fan, things could be better in noise output. 

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Protection Features

Check out our PSUs 101 article to learn more about PSU protection features.

OCP at 12V and OPP are highly set, most likely to cope with power spikes. That is not the best way to do it since it makes the PSU’s protection features less effective. On the minor rails, the OCP triggering points are correctly set. 

DC Power Sequencing

According to Intel’s most recent Power Supply Design Guide (revision 1.4), the +12V and 5V outputs must be equal to or greater than the 3.3V rail at all times. Unfortunately, Intel doesn’t mention why it is so important to always keep the 3.3V rail’s voltage lower than the levels of the other two outputs.

No problems here since the 3.3V rail is always lower than the other two. 

Cross Load Tests

To generate the following charts, we set our loaders to auto mode through custom-made software before trying more than 25,000 possible load combinations with the +12V, 5V, and 3.3V rails. The deviations in each of the charts below are calculated by taking the nominal values of the rails (12V, 5V, and 3.3V) as point zero. The ambient temperature during testing was between 30 to 32 degrees Celsius (86 to 89.6 degrees Fahrenheit).

Load Regulation Charts

Efficiency Graph

Ripple Graphs

The lower the power supply’s ripple, the more stable the system will be and less stress will also be applied to its components.

Infrared Images

We apply a half-load for 10 minutes with the PSU’s top cover and cooling fan removed before taking photos with a modified Fluke Ti480 PRO camera able to deliver an IR resolution of 640×480 (307,200 pixels).

The board holding the 12V FETs is the spot reporting the highest temperatures. Still, we didn’t notice alarmingly high temperatures, thanks to the highly efficient platform that minimizes energy losses. 

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Advanced Transient Response Tests

For details about our transient response testing, please click here.

In the real world, power supplies are always working with loads that change. It’s of immense importance, then, for the PSU to keep its rails within the ATX specification’s defined ranges. The smaller the deviations, the more stable your PC will be with less stress applied to its components. 

We should note that the ATX spec requires capacitive loading during the transient rests, but in our methodology, we also choose to apply a worst case scenario with no additional capacitance on the rails. 

Advanced Transient Response at 20% – 20ms

Advanced Transient Response at 20% – 10ms

Advanced Transient Response at 20% – 1ms

Advanced Transient Response at 50% – 20ms

Advanced Transient Response at 50% – 10ms

Advanced Transient Response at 50% – 1ms

Transient response is good at 12V, 3.3V and 5VSB and satisfactory at 5V. 

Turn-On Transient Tests

In the next set of tests, we measure the PSU’s response in simpler transient load scenarios—during its power-on phase. Ideally, we don’t want to see any voltage overshoots or spikes since those put a lot of stress on the DC-DC converters of installed components.

We didn’t notice any notable voltage overshoots or voltage spikes, in these tests. 

Power Supply Timing Tests

There are several signals generated by the power supply, which need to be within specified, by the ATX spec, ranges. If they are not, there can be compatibility issues with other system parts, especially mainboards. From year 2020, the PSU’s Power-on time (T1) has to be lower than 150ms and the PWR_OK delay (T3) from 100 to 150ms, to be compatible with the Alternative Sleep Mode.

The PWR_OK delay is within the 100-150ms region, so the PSU supports the alternative sleep mode recommended by the ATX spec.

Ripple Measurements

Ripple represents the AC fluctuations (periodic) and noise (random) found in the PSU’s DC rails. This phenomenon significantly decreases the capacitors’ lifespan because it causes them to run hotter. A 10-degree Celsius increase can cut into a cap’s useful life by 50%. Ripple also plays an important role in overall system stability, especially when overclocking is involved.

The ripple limits, according to the ATX specification, are 120mV (+12V) and 50mV (5V, 3.3V, and 5VSB).

Ripple suppression is good on all rails. 

Ripple At Full Load

Ripple At 110% Load

Ripple At Cross-Load 1

Ripple At Cross-Load 4

EMC Pre-Compliance Testing – Average and Quasi-Peak EMI Detector Results

Electromagnetic Compatibility (EMC) is the ability of a device to operate properly in its environment without disrupting the proper operation of other nearby devices.

Electromagnetic Interference (EMI) is the electromagnetic energy a device emits, and it can cause problems in other nearby devices if too high. For example, it can cause increased static noise in your headphones or/and speakers.

΅We use TekBox’s EMCview to conduct our EMC pre-compliance testing.

EMI emissions are low, with both the average and peak EMI detectors. 

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Performance Rating

Overall performance tops the chart. 

Noise Rating

The graph below depicts the cooling fan’s average noise over the PSU’s operating range, with an ambient temperature between 30 to 32 degrees Celsius (86 to 89.6 degrees Fahrenheit).

The EVGA 850 G7 is not noisy under average loads and operating temperatures, but it will get loud if you push it hard. This affects its overall noise output. 

Efficiency Rating

The following graph shows the PSU’s average efficiency throughout its operating range with an ambient temperature close to 30 degrees Celsius.

The 850 G7 is highly efficient.

Power Factor Rating

The following graphs show the PSU’s average power factor reading throughout its operating range with an ambient temperature close to 30 degrees Celsius and 115V/230V voltage input. 

The APFC converter has good performance with 115V, while there is room for improvement with 230V input. 

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The EVGA 850 G7 is one of the best 850W units the market today. The Corsair RM850x (2021) is close in performance and has an advantage in noise output, while the 850 G6 loses notably in performance but achieves a significant win in noise output. The performance FSP delivered out of such a compact platform is impressive. We can’t stop thinking, though, about the improvement in noise output with a larger PCB and cooling fan. Downsizing high-capacity PSUs at that degree comes at a cost, of increased noise output, under harsh conditions.

Besides the tiny footprint, the top performance, the fully modular cable design and the high build quality, EVGA threw in LED load indicators on one of the PSU’s sides. Someone can argue that it would be better if an external PCB hosted these LED indicators, which the user could install on top of their desk to be easily accessible. This sounds good, but it would also likely increase the cost. We also noticed is that FSP used two different bulk caps in this unit, with the second provided by a less known manufacturer. We would like to see both caps have the same quality. 

The EVGA 850 G7 brings up memories of the legendary G2 units, which were among the best PSUs that EVGA ever offered. We are eager to see the upgraded G7 versions featuring the new 12+4 pin PCIe connectors and ATX 3.0 support.

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Disclaimer: Aris Mpitziopoulos is Tom’s Hardware’s PSU reviewer. He is also the Chief Testing Engineer of Cybenetics and developed the Cybenetics certification methodologies apart from his role on Tom’s Hardware. Neither Tom’s Hardware nor its parent company, Future PLC, are financially involved with Cybenetics. Aris does not perform the actual certifications for Cybenetics.