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Gigabyte UD750GM Power Supply Review

Decent, efficient, and with a reasonable price tag.

Gigabyte UD750GM
(Image: © Tom's Hardware)

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

VoltageBeforeAfterChangePass/Fail
12V12.091V11.766V2.69%Pass
5V5.120V4.999V2.36%Pass
3.3V3.371V3.190V5.37%Pass
5VSB5.054V4.982V1.42%Pass

Advanced Transient Response at 20% – 10ms

VoltageBeforeAfterChangePass/Fail
12V12.091V11.757V2.76%Pass
5V5.120V4.999V2.36%Pass
3.3V3.372V3.190V5.39%Pass
5VSB5.055V4.984V1.40%Pass

Advanced Transient Response at 20% – 1ms

VoltageBeforeAfterChangePass/Fail
12V12.091V11.788V2.50%Pass
5V5.120V5.032V1.72%Pass
3.3V3.372V3.177V5.78%Pass
5VSB5.055V4.988V1.33%Pass

Advanced Transient Response at 50% – 20ms

VoltageBeforeAfterChangePass/Fail
12V12.071V11.915V1.29%Pass
5V5.101V4.995V2.09%Pass
3.3V3.349V3.156V5.77%Pass
5VSB5.028V4.957V1.41%Pass

Advanced Transient Response at 50% – 10ms

VoltageBeforeAfterChangePass/Fail
12V12.071V11.903V1.40%Pass
5V5.101V4.982V2.33%Pass
3.3V3.349V3.160V5.64%Pass
5VSB5.028V4.958V1.40%Pass

Advanced Transient Response at 50% – 1ms

VoltageBeforeAfterChangePass/Fail
12V12.071V11.879V1.59%Pass
5V5.101V4.989V2.19%Pass
3.3V3.349V3.171V5.33%Pass
5VSB5.028V4.968V1.19%Pass

The PSU didn't fail in any of these tests, but transient response is mediocre on all rails. 

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 noticed a small voltage step at 5VSB, which won't create any issues, and another one at 12V, from PSU off to full load state. The latter looks and is small, so most likely, it won't create any problems. 

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.

T1 (Power-on time) & T3 (PWR_OK delay)
LoadT1T3
20%66136
100%67135

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).

Test12V5V3.3V5VSBPass/Fail
10% Load7.9 mV14.3 mV10.0 mV16.0 mVPass
20% Load9.3 mV15.9 mV11.9 mV15.8 mVPass
30% Load16.1 mV17.2 mV12.3 mV20.5 mVPass
40% Load13.2 mV16.2 mV13.1 mV17.8 mVPass
50% Load14.3 mV18.2 mV14.8 mV17.8 mVPass
60% Load14.1 mV19.1 mV17.3 mV16.4 mVPass
70% Load15.9 mV21.6 mV19.7 mV17.5 mVPass
80% Load17.2 mV22.1 mV22.1 mV17.3 mVPass
90% Load17.8 mV23.2 mV23.4 mV18.0 mVPass
100% Load26.4 mV26.6 mV25.5 mV21.7 mVPass
110% Load28.9 mV26.8 mV28.3 mV22.3 mVPass
Crossload 110.4 mV25.6 mV29.0 mV15.5 mVPass
Crossload 28.8 mV17.7 mV31.8 mV14.8 mVPass
Crossload 38.2 mV24.3 mV17.7 mV14.8 mVPass
Crossload 424.9 mV15.4 mV11.0 mV19.1 mVPass

Ripple suppression is good, but the competition is extra challenging in this area. 

Ripple At Full Load

Ripple At 110% Load

Ripple At Cross-Load 1

Ripple At Cross-Load 4

EMC Pre-Compliance Testing – Average & 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) stands for 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.

(Image credit: Tom's Hardware)

Everything is under control in EMI emissions. 

MORE: Best Power Supplies

MORE: How We Test Power Supplies

MORE: All Power Supply Content

Aris Mpitziopoulos
Aris Mpitziopoulos

Aris Mpitziopoulos is a Contributing Editor at Tom's Hardware US, covering PSUs.

  • Tom Sunday
    I will shortly be in the market for a new PSU and as part of a complete new generation ‘PC Build’ this coming December. Due to the extreme system importance of a PSU selection I never at first look at the pricing or its reasonable cost compared to other brands. But surely a 10-year unblemished warranty has usually driven me to EVGA and SEASONIC products. I am also now prone in looking at PSU’s with over 1200W as the new 4000 series GPU’s and other hardware coming on stream will become so much more demanding and power hungry. Enthusiasts I believe will also now be keeping their primary “Builds” much longer (5-years or more?) as hardware cost are spiraling out of control. So 10-year warranties and RMA services area big deal for me among many other expected PSU offerings like direct software control, digital readouts on the PSU itself, high quality cabling and product finishes.
    Reply
  • PiranhaTech
    I'm curious if you did the GamersNexus tests. A lot of PC builders are going to wait for their tests before considering a Gigabyte PSU due to the exploding PSU issue they had

    aACtT_rzToIView: https://www.youtube.com/watch?v=aACtT_rzToI
    Reply