XPG Core Reactor 750W 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 and, at the same time, it applies less stress to the DC-DC converters that many system components utilize.

The load regulation at +12V is loose compared to other similar spec units. We expected within 1% deviation on this rail. On the other hand, all minor rails have a tight load regulation.

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 exceeds 21ms, while the ATX spec requires at least 17ms. The power-ok signal is higher than 16ms, and it is accurate since it has a longer than 1ms delay from the PSU's hold-up time.

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.

The inrush current is low with 115V, and pretty high with 230V. 

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's fan operates at low speeds up to the 50% load test, despite the high operating temperatures. Moreover, the power supply doesn't have a problem operating under high loads with increased temperatures for prolonged periods. Nonetheless, such scenarios force the cooling fan to spin at high speeds, where the noise output exceeds 40 dB(A).

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 efficiency levels under light loads are impressive. 

2% or 10W Load Test

Intel plans on raising the ante at efficiency levels under ultra-light loads. So from July 2020, the ATX spec will require 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.

With 2% of its max-rated-capacity, load the unit exceeds 70% efficiency, as the ATX spec will require from July 2020. 

Efficiency

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 Core Reactor 750 meets most of the competing offerings with normal loads, while with light and super-light loads it achieves second place. 

5VSB Efficiency

CWT, the OEM of this unit, used one of its "good" 5VSB regulation circuits, so the registered efficiency levels are pretty high. 

Power Consumption In Idle and Standby

The phantom power levels are dead low, with both voltage inputs. 

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 profile at high temperatures is looser compared to the 850W Core Reactor model that we evaluated a while ago. Still, it could be even more relaxed. 

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

With up to 410W loads, the PSU is inaudible. It takes more than 560W to exceed 30 dB(A), but in no case does the noise goes over 35 dB(A). If we haven't tested the Corsair RM750x, which is one of the quietest 750W units, we would be highly impressed by this unit's silent operation.

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