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

The Gigabyte UD1000GM PG5 is the first PSU available on the market with a 12+4 pin PCIe connector.

Gigabyte UD1000GM PG5
(Image: © Shutterstock, Tom's Hardware)

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Protection Features

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

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OCP (Cold @ 27°C)12V: 105.2A (126.29%), 11.973V
5V: 35A (140%), 5.177V
3.3V: 30.5A (122%), 3.340V
5VSB: 4.6A (153.33%), 4.959V
OCP (Hot @ 39°C)12V: 105.2A (126.29%), 11.981V
5V: 34.1A (136.4%), 5.163V
3.3V: 30.3A (121.2%), 3.340V
5VSB: 4.6A (153.33%), 4.958V
OPP (Cold @ 28°C)1239.04W (123.9%)
OPP (Hot @ 40°C)1236.02W (123.6%)
OTP✓ (151°C @ 12V Heat Sink)
SCP12V to Earth: ✓
5V to Earth: ✓
3.3V to Earth: ✓
5VSB to Earth: ✓
-12V to Earth: ✓
PWR_OKAccurate but lower than 16ms
NLO
SIPSurge: MOV
Inrush: NTC Thermistor

The OCP triggering points are correctly set at 12V and 3.3V, which goes for OPP, too. At 5V, there is no need for 34-35A triggering points. Finally, it is weird that there is no relay for the NTC thermistor. There was no room to install one. Still, it is not acceptable for a PSU of this price and category to not have a bypass relay, which allows the NTC thermistor to cool down fast. 

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

(Image credit: Tom's Hardware)

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 640x480 (307,200 pixels).

Despite the harsh conditions, the temperatures in most parts are low. The hottest part is the NTC thermistor because it lacks a bypass relay. MEIC and Gigabyte should address this shortcoming ASAP because the inrush current will go through the roof in a hot-start with the bulk cap empty. 

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Aris Mpitziopoulos
Contributing Editor

Aris Mpitziopoulos is a contributing editor at Tom's Hardware, covering PSUs.