Gigabyte UD1000GM PG5 Review: The First PCIe Gen 5 Compatible PSU

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.

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Load regulation is tight at 12V and 5VSB, and mediocre on the minor 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.

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The hold-up time is at 17ms, aligning with the ATX spec's requirements. On the other hand, the power ok signal does not exceed 16ms. It is accurate, at least. 

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.

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Inrush current is not so high with 115V, but this not the case with 230V. 

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 doesn't have a problem under harsh conditions, but don't expect it to be quiet. The passive operation lasted till 20% load in our tests, with the fan starting right away at almost 1100 RPM, which is too high. MEIC wants to ensure that the not-so-high quality caps on the secondary side will be ok under all conditions and outlive the warranty. 

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 fan doesn't spin at light loads, even at increased temperatures, so the PSU is silent. The efficiency levels are satisfactory, too. 

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.

With a 2% load, efficiency is above 70%, which is what the ATX spec recommends. 

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.

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Even for the Gold standards, this platform is highly efficient in all load regions (high, low, and super-light). The APFC converter has decent performance. 

5VSB Efficiency

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The 5VSB rail is highly efficient. 

Power Consumption In Idle And Standby

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Vampire power is increased. Ideally, it should be below 0.1W. 

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 speed profile is aggressive. The compact dimensions of the PSU, the 120mm fans, and the low-grade caps on the secondary side don't leave room for lower fan speeds at high operating temperatures. 

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

At average operating temperatures close to 30 degrees Celsius, the PSU is silent with up to 250W loads. The problem is that right after that, the PSU's noise exceeds 30 dBA. With around 680W, the fan's noise enters the 35-40 dBA range. With 750W, it goes above 40 dBA, and it passes the 45 dBA mark with around 930W loads. All in all, this is a noisy PSU. 

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