Introduction

We would like to thank Gigabyte for supplying the review sample.


Gigabyte is mostly known for its motherboards and graphics cards rather than its power supplies. As such, I found it quite surprising that their site lists a total of 77 PSU models! While most of these address the mainstream market, there are also enough higher-end models on offer.

According to Gigabyte, the P750GM and P850GM are ideal for power-hungry graphics cards, like the NVIDIA RTX 3080 and newly released AMD RX 6800 and RX 6800XT. Both PSUs are fully modular and compact because of their limited depth of 140 mm.

The P750GM is 80 PLUS Gold certified, as well as ETA-A and LAMBDA-A- certified for, respectively, efficiency and noise on the Cybenetics scale. These are relatively high ratings, showing that this is an efficient and quiet PSU. Gigabyte supports this product with a five-year warranty, which is satisfactory—PSU life expectancy highly depends on operating conditions and mains grid power quality. To boost reliability, a hydraulic bearing fan is used, at least according to Gigabyte. As it turns out, it is actually a plain rifle bearing fan.

Moreover, the bulk cap is provided by a Japanese manufacturer, so it will last for a while. Lastly, all protection features are advertised as present, which has it look like a fine product on paper. I plan to run many tests to check on whether these claims from Gigabyte are valid.

Specifications

Photos

At the front, we find a pretty large 80 PLUS Gold badge, the model number, and four smaller badges depicting the most notable features. On the back is a features list, the power specifications table, and a description of all available connectors and cable lengths.


The PSU is well protected inside the box. Additions only consist of four fixing bolts, the modular cables, and the AC power cord. There are no zip ties or Velcro straps.


The front consists of the honey-comb exhaust grill, AC receptacle, and power switch.


The large power specifications label is found on the bottom


The modular board hosts ten sockets in total. The EPS and PCIe sockets are identical and electrically compatible.


Measuring only 140 mm deep, this is a very compact 750 W PSU.

Cables and Connectors

There are two EPS and four PCIe cables, which is enough for a 750 W PSU, but I spot two problems here. Firstly, the EPS connector should at least be 650 mm long, and secondly, there are no dedicated PCIe cables. If you plan on using a power-hungry GPU, keep in mind that you cannot use a single PCIe cable with two connectors. This cable and, more specifically, its plug on the PSU, won't be able to handle the load, which can lead to catastrophic results for both the PSU and the connected graphics card. If dedicated PCIe connectors were provided, there wouldn't be any such issue. With the current configuration, you will have to use two cables with four PCIe connectors in total for a single graphics card, which also means dealing with the two unused connectors.


The distance between SATA connectors is ideal, which is not the case for the 4-pin Molex connectors as they aren't far enough apart.

Component Analysis

Before reading this page, we strongly suggest a look at this article, which will help you understand the insides of a PSU better.



This platform looks to be made by MEIC, which also makes the AORUS P850 and P750 units. The design is very clean, with no cables blocking airflow, and the heatsinks are very small. Build quality is high, but lower-end manufacturers provide some of the key components. I am referring to the APFC and primary switching FETs. The capacitors on the secondary side are provided by an unknown manufacturer—I couldn't find any detailed information on these caps.


The transient filter uses four Y and a pair of X caps, two CM chokes, a discharge IC, and an MOV.


Surge and inrush current protections are handled by an MOV and an NTC thermistor-relay combination.


The two bridge rectifiers can handle up to 20 A combined.


The APFC converter uses two Jilin Sino-Microelectronics FETs and a single boost diode provided by the same manufacturer. Chemi-Con provides the bulk cap, and it does not have enough capacity to allow for a hold up time of over 17 ms.


Jilin Sino-Microelectronics provides the main FETs, and as you can see, they didn't survive my tests. They died in a glorified way, making one of the loudest bangs I have ever heard. The main FETs are arranged in a half-bridge topology, and an LLC resonant converter is also used to boost efficiency. The resonant controller is a Champion CM6901X.


Four NCE Power FETs regulate the +12 V rail.


The VRMs handling the minor rails use four Alpha & Omega FETs and a pair of uPI-Semi PWM controllers.


I have never encountered these cap brands before, so I am very skeptical about their reliability. Besides electrolytic caps, a dozen polymers are also used, provided by an unknown manufacturer.


The 5VSB circuit uses an SBR on its secondary side, and the standby PWM controller is a PR6249H IC.


The modular board hosts four electrolytic and two polymer caps. Four bus bars connect this board to the main one.


Soldering quality is good.


Some SMD components are not correctly aligned, but this is not a significant issue as long as they are properly soldered to the PCB.


The rifle bearing fan is provided by Yate Loon. Mostly known for affordable products, their fans cannot compete with high-end fans.


Gigabyte advertises it as a hydraulic dynamic bearing, but I broke it apart to find that it uses a rifle bearing. Still better than a plain sleeve bearing, it is inferior to a true HDB/FDB.