Introduction

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


Cougar recently introduced the GX-F line consisting of three members with capacities ranging from 550–750 W. All are fully modular and 80 PLUS Gold certified. They are also certified by Cybenetics with ETA-A (88-91% efficiency), LAMBDA-A- (25-30 dB[A], GX-F-550), and LAMBDA-Standard++ (30-35 dB[A]), GX-F650/750) ratings. The chassis in those new Cougar units is compact enough with 15 cm of depth, and its external design looks nice. Internally, the platform is provided by HEC/Compucase, and according to our sources, it is a new design developed for Cougar specifically.

In this review, we will focus on the strongest GX-F member with 750 W maximum power output. The GX-F750 is currently sold for €100 at Caseking.de, one of the largest online shops (and distributors) in Europe, which is €20 less than the highly popular Corsair RM750x, and the Seasonic Focus Plus Gold with a similar capacity has about the same price tag (€104), while the Bitfenix Whisper M 750 W is ten euros away since it currently goes for €110. This means that the Cougar GX-F750 faces strong competition in Bitfenix's offer and even stronger competition from Seasonic's offer, so it will have to prove that it can meet both those PSUs face-on in our testing session.

Specifications

The ETA-A and 80 PLUS Gold ratings are common for PSUs with 750 W max power in this price range, but some have much better noise ratings than LAMBDA-S++. Take, for example, the RM750x (both the old and new version) with an LAMBDA-A (15-20 db[A] overall noise output) rating. The Bitfenix BWG750M also manages less than 30 dB(A) overall noise output for a LAMBDA-A- rating.

According to Cougar, all protection features are present, while the maximum operating temperature for a continuous full load operation is 50°C. The PSU's cooling is taken care of by a 135 mm fan equipped with a hydro dynamic bearing, which is just another name for the fluid dynamic bearing and allows companies to avoid paying the patent fees that come with the FDB naming scheme. There is no semi-passive operation, which could help keep noise output low under light and moderate loads, while the PSU's dimensions are pretty compact with 15 cm of depth. Finally, the provided warranty is long at seven years, and the MSRP for the US market, once the PSU becomes available there, will be around $100.


The maximum combined power the minor rails can deliver is too high for a modern system's needs. Typically, the +12V rail can deliver almost the unit's full power alone, while the 5VSB rail can output up to three amps.

Cables and Connectors, Power Distribution

Four PCIe connectors are enough for a 750 W PSU, but one EPS connector definitely is not. Cougar should equip this PSU with a second EPS connector in order to make it compatible with mainboards requiring more energy for the CPU socket's area. More clearance between the peripheral connectors would also be nice.


Here are some photos of the unit's cables.

Since this PSU features a single +12V rail, we do not have anything to comment on when it comes to its power distribution.

Unboxing Video

The following video footage shows the unboxing of the GX-F750.



Here are some photos of the box and its bundle.


This is the PSU's front.


The power specification's labels are installed on the unit's sides, while there is only a sticker showing the serial number on the unit's bottom.


This is the fully modular panel.


We took a bunch of photos of the PSU, so here are some more for you to take a look at.

A Look Inside and Component Analysis

Before reading this page, we strongly suggest a look at this article, which will help you understand the internal components of a PSU much better. Our main tool for the disassembly of the PSU is a Thermaltronics TMT-9000S soldering and rework station. It is of extreme quality and is equipped with a matching de-soldering gun. For the identification of tiny parts, we use an Andonstar HDMI Digital Microscope.



The main PCB is compact, and the platform uses a contemporary design in order to achieve efficiency levels that are high enough for today's standards. On the primary side, a half-bridge topology is utilized, along with an LLC resonant converter, while six FETs on the secondary side handle the +12V rail and a couple of DC-DC converters generate the minor rails. It would have been nice of HEC to avoid Teapo SC caps in the secondary side since they have a pretty low lifetime and are not considered all that reliable.


The transient filter consists of four Y caps, two X caps, two CM chokes, an MOV, and an MPS HF81 that is described as an X capacitor bleeder by its manufacturer. The HF81's operation is simple: once placed in series with discharge or bleed resistors, it acts as a high-voltage switch. In the presence of AC voltage, the HF81 blocks current flow to the bleed resistors to minimize the power loss on these components. When disconnected from the AC voltage, the HF81 automatically discharges the X capacitor by closing the circuit through the bleed resistors and directing the energy away from the exposed AC plug.


There is a single bridge rectifier, which we couldn't identify without removal from the PCB.


The APFC converter uses two Infineon IPA60R125P6 FETs and a single boost diode (Hestia H2S060H006). The bulk cap is provided by Chemi-Con and belongs to the KMW series.


The APFC converter's controller is a Champion CM6502S, installed on a small daughter-board.


There is an NTC thermistor for protection against large inrush currents. It is supported by a bypass relay.


The primary FETs, two Infineon IPP65R150CFDs, are installed into a half-bridge topology. An LLC resonant converter is also used to provide higher efficiency. The controller responsible for these parts is a Champion CM6901.


A large board on the secondary side holds all six FETs that regulate the +12V rail. The same board hosts the LLC resonant controller. A small heatsink is used for improved cooling on the +12V FETs.


The board hosting the +12V FETs is connected to the main transformer through several bus bars. This way, energy losses are highly reduced.


The filtering caps in the secondary side are from Chemi-Con and Teapo. The Chemi-Con caps are of high quality since they belong to the KY line, but the Teapo caps are from a low-end line and have no place in a PSU going for $100. Besides electrolytic caps, we also find some APAQ polymer filtering caps.


A couple of DC-DC converters generate the minor rails. They use two TI CSD87355Q5D power blocks and two Anpec APW7073 PWM controllers.


The 5VSB circuit is regulated by a PFR10L60CT SBR, and the standby PWM controller is a TinySwitch-III TNY280PN.


The -12V rail uses a KIA7912PI regulator IC instead of a plain diode.


The soldering quality is decent overall, however there is definitely room for improvement in this section.


The cooling fan is made by Globe Fan, and its model number is RL4Z S1352512H. It measures 135 mm across and uses a hydro dynamic bearing along with specially designed blades. This is a mid-speed fan, but its fan profile is aggressive under tough conditions.