Cougar GX 700 W Power Supply Review

[nextpage title=”Introduction”]

The Cougar GX is another 80 Plus Gold power supply series to arrive on the market. Does the 700 W model deliver the efficiency promised by the manufacturer? Let’s check it out.

Cougar is based in Germany and belongs to HEC/Compucase, that manufactures all their power supplies.

Figure 1: Cougar GX 700 W power supply

Figure 2: Cougar GX 700 W power supply

The Cougar GX 700 W is 7.1” (180 mm) deep, using a fluid dynamic 140 mm fan on its bottom. The fan part number, PLA14025S12M, makes us believe that it is manufactured by Power Logic, even though the brand, “Cougar,” is printed on it.

This unit features active PFC, of course.

The GX 700 W comes with a modular cabling system with eight connectors, four red ones for video card power cables and four black ones for peripheral and SATA power connectors. Four cables are permanently attached to the power supply. The cables included are the following:

• Main motherboard cable with a 20/24-pin connector, 25.2” (64 cm) long (permanently attached to the power supply)
• One cable with one EPS12V connector, two ATX12V connectors that together form another EPS12V connector, and another ATX12V connector, 24.4” (62 cm) to the first connector and 11” (28 cm) between connectors (permanently attached to the power supply)
• One cable with one six-pin connector for video cards, 20.9” (53 cm) long (permanently attached to the power supply)
• One cable with one six/eight-pin connector for video cards, 20.9” (53 cm) long (permanently attached to the power supply)
• Two cables, each with one six/eight-pin connector for video cards, 19.7” (50 cm) long (modular cabling system)
• One cable with four SATA power connectors, 20.5” (52 cm) to the first connector, 5.9” (15 cm) between connectors (modular cabling system)
• One cable with three SATA power connectors and two standard peripheral power connectors, 20.5” (52 cm) to the first connector, 5.9” (15 cm) between connectors (modular cabling system)
• One cable with two SATA power connectors and two standard peripheral power connectors, 20.5” (52 cm) to the first connector, 5.9” (15 cm) between connectors (modular cabling system)
• One cable with two standard peripheral power connectors, 20.5” (52 cm) to the first connector, 5.9” (15 cm) between connectors (modular cabling system)
• One adapter to convert one standard peripheral power connector into a floppy disk drive power connector.

All wires are 18 AWG, except the ones in the main motherboard cable and in the cable with a six-pin connector that is permanently attach to the power supply, which are thicker (16 AWG).

The configurations and lengths of the cables are perfect. The power supply allows you to have up to two video cards that require two auxiliary power connectors each, and if you pay attention, the power supply comes with two connectors for video card power cables that are left unused on the modular cabling system, allowing you to install up to three video cards that require two power connectors each, if you buy the additional cables.

Figure 3: Cables

Now let’s take an in-depth look inside this power supply.

[nextpage title=”A Look Inside The Cougar GX 700 W”]

We decided to disassemble this power supply to see what it looks like inside, how it is designed, and what components are used. Please read our Anatomy of Switching Power Supplies tutorial to understand how a power supply works and to compare this power supply to others.

This page will be an overview, and then in the following pages we will discuss in detail the quality and ratings of the components used. 

Figure 4: Top view

Figure 5: Front quarter view

Figure 6: Rear quarter view

Figure 7: Printed circuit board

[nextpage title=”Transient Filtering Stage”]

As we have mentioned in other articles and reviews, the first place we look when opening a power supply for a hint about its quality, is its filtering stage. The recommended components for this stage are two ferrite coils, two ceramic capacitors (Y capacitors, usually blue), one metalized polyester capacitor (X capacitor), and one MOV (Metal-Oxide Varistor). Very low-end power supplies use fewer components, usually removing the MOV and the first coil. 

In this power supply, this stage is flawless. It has two X capacitors and two Y capacitors more than the minimum required.

Figure 8: Transient filtering stage (part 1)

Figure 9: Transient filtering stage (part 2)

In the next page we will have a more detailed discussion about the components used in the Cougar GX 700 W.

[nextpage title=”Primary Analysis”]

On this page we will take an in-depth look at the primary stage of the Cougar GX 700 W. For a better understanding, please read our Anatomy of Switching Power Supplies tutorial.

This power supply uses two GBU806 rectifying bridges connected in parallel on
its primary, and they  are connected to the same heatsink as the active PFC transistors and diode. Each bridge supports up to 8 A at 100° C, so in theory, you would be able to pull up to 1,840 W from a 115 V power grid. Assuming 80% efficiency, the bridges would allow this unit to deliver up to 1,472 W without burning themselves out. Of course, we are only talking about these components, and the real limit will depend on all the other components in this power supply.

Figure 10: Rectifying bridges

The active PFC circuit uses three SPP20N60C3 MOSFETs, each one capable of delivering up to 20.7 A at 25° C or up to 13.1 A at 100° C in continuous mode (note the difference temperature makes), or up to 62.1 A in pulse mode at 25° C. These transistors present a 190 mΩ resistance when turned on, a characteristic called RDS(on). The lower this number the better, meaning that the transistors will waste less power and the power supply will achieve a higher efficiency.

Figure 11: Active PFC transistors and diode.

The electrolytic capacitor used to filter the output of the active PFC circuit is Japanese, from Chemi-Con, and labeled at 105° C.

In the switching section, two FCP20N60 power MOSFET transistors are used in the traditional two-transistor forward configuration, each one being capable of delivering up to 20 A at 25° C or up to 12.5 at 100° C in continuous mode, or up to 60 at 25° C in pulse mode, with an RDS(on) of 150 mΩ.

Figure 12: Switching transistors

The primary is controlled by a CM6802 active PFC/PWM combo.

Figure 13: Active PFC/PWM combo controller

Now let’s take a look at the secondary of this power supply.

[nextpage title=”Secondary Analysis”]

This power supply uses a synchronous design in its secondary, meaning that the Schottky rectifiers were replaced by MOSFET transistors in order to increase efficiency. On top of that this unit uses a DC-DC design, meaning that this unit is basically a +12 V power supply, with the +5 V and +3.3 V outputs being generated by two small power supplies attached to the +12 V output.

The +12 V output is generated by four IPP032N06N3 MOSFETs, each one capable of handling up to 120 A at 100° C in continuous mode, or up to 480 A at 25° C in pulse mode, with an RDS(on) of only 2.9 mΩ. In this power supply the +12 V output is also used to generate the +5 V and the +3.3 V outputs, as you know. As an exercise, if we assume that all load was exclusively pulled from the +12 V output, we would have a maximum theoretical current limit of 343 A or 4,114 W.

Figure 14: Transistors in charge of the +12 V rectification (on the far left we have the +5VSB rectifier and on the far right we have the -12 V voltage regulator)

Instead of having only one +12 V coil, this power supply has two. Each pair of transistors are connected to a separate coil, and we guess that they switch out of phase (i.e., while one coil is conducting, the other is charging).

The +5 V and the +3.3 V outputs are generated by two small power supplies available on small daughterboards attached to the +12 V rail. Each of these power supplies is comprised of two APM2510N MOSFETs, two APM2556N MOSFETs (60 A at 25° C or 48 A at 100° C, 7.5 mΩ resistance), and one APW7073 PWM controller. They use solid capacitors.

Figure 15: One of the DC-DC converters

The outputs are monitored by a PS223 integrated circuit that is soldered on the printed circuit board shown in Figure 16. This circuit supports over voltage (OVP), under voltage (UVP) and over current (OCP) protections. This circuit offers four over current protection channels (one for +3.3 V, one for +5 V, and two for +12 V). An LM393 voltage comparator is also present, probably to increase the number of +12 V OCP channels to four in order to match the number of +12 V rails advertised by the manufacturer.

Figure 16: Monitoring circuit

The Cougar GX 700 W uses solid capacitors to filter the +12 V, +5 V and +3.3 V lines, but some regular electrolytic capacitors from Teapo are also used on the +12 V line and on the +5VSB line, and two capacitors from Su’scon are used on the -12 V line.

[nextpage title=”Power Distribution”]

In Figure 17, you can see the power supply label containing all the power specs.

Figure 17: Power supply label

The available rails are distributed like this:

• +12V1 (solid yellow wires): Main motherboard cable, SATA and peripheral power cables
• +12V2 (yellow/black wires): Half of the EPS12V connectors and an ATX12V connector
• +12V3 (yellow/blue wires): The other half of the EPS12V connectors, a six/eight-pin connector labeled “PCI-E2,” and two of the red connectors of the modular cabling system
• +12V4 (yellow/
  green wires): A six-pin connector labeled “PCI-E,” and two of the red connectors of the modular cabling system

The modular cabling system has the rails labeled – or sort of. While the black connectors (which are connected to the SATA and peripheral power plugs) are correctly identified as “+12V1,” two of the red connectors (for video card power cables) are labeled as “+12V5” (the correct label would be “+12V4”), and the other two are labeled as “+12V6” (the correct label would be “+12V3”).

This distribution separates the CPU (ATX12V/EPS12V connectors) from the video cards. When installing a second video card, make sure to connect one of the cables to the +12V4 rail (labeled “+12V5”) and the other cable to the +12V3 rail (labeled “+12V6”).

Now let’s see if this power supply can really deliver 700 W.

[nextpage title=”Load Tests”]

We conducted several tests with this power supply, as described in the article, Hardware Secrets Power Supply Test Methodology.  

First we tested this power supply with five different load patterns, trying to pull around 20%, 40%, 60%, 80%, and 100% of its labeled maximum capacity (actual percentage used listed under “% Max Load”), watching the behavior of the reviewed unit under each load. In the table below, we list the load patterns we used and the results for each load.

If you add all the power listed for each test, you may find a different value than what is posted under “Total” below. Since each output can vary slightly (e.g., the +5 V output working at +5.10 V), the actual total amount of power being delivered is slightly different than the calculated value. In the “Total” row, we are using the real amount of power being delivered, as measured by our load tester.

The +12VA and +12VB inputs listed below are the two +12 V independent inputs from our load tester. During this test the +12VA input was connected to the power supply +12V1 and +12V4 rails, while the +12VB input was connected to the power supply +12V2 and +12V3 rails (EPS12V connector).

Input	Test 1	Test 2	Test 3	Test 4	Test 5
+12VA	4.5 A (54 W)	9.5 A (114 W)	14.5 A (174 W)	19 A (228 W)	25 A (300 W)
+12VB	4.5 A (54 W)	9.5 A (114 W)	14.5 A (174 W)	19 A (228 W)	25 A (300 W)
+5V	2 A (10 W)	4 A (20 W)	6 A (30 W)	8 A (40 W)	10 A (50 W)
+3.3 V	2 A (6.6 W)	4 A (13.2 W)	6 A (19.8 W)	8 A (26.4 W)	10 A (33 W)
+5VSB	1 A (5 W)	1.5 A (7.5 W)	2 A (10 W)	2.5 A (12.5 W)	3 A (15 W)
-12 V	0.5 A (6 W)	0.5 A (6 W)	0.5 A (6 W)	0.5 A (6 W)	0.5 A (6 W)
Total	137.3 W	276.5 W	413.4 W	537.3 W	698.8 W
% Max Load	19.6%	39.5%	59.1%	76.8%	99.8%
Room Temp.	45.2° C	46.0° C	47.0° C	48.3° C	45.4° C
PSU Temp.	42.2° C	44.2° C	45.7° C	46.7° C	47.3° C
Voltage Regulation	Pass	Pass	Pass	Pass	Pass
Ripple and Noise	Pass	Pass	Pass	Pass	Pass
AC Power	159.6 W	312.3 W	469.6 W	616.0 W	813.0 W
Efficiency	86.0%	88.5%	88.0%	87.2%	86.0%
AC Voltage	113.1 V	111.5 V	110.1 V	109.0 V	106.3 V
Power Factor	0.986	0.991	0.996	0.997	0.998
Final Result	Pass	Pass	Pass	Pass	Pass

The Cougar GX 700 W can really deliver its labeled wattage at high temperatures.

Efficiency was always very high, between 86% and 88.5%. Nice numbers, but there is just one small detail: this unit has the 80 Plus Gold certification and should be able to deliver 87% efficiency at light (20%) and full loads, and 90% efficiency at typical (50%) load. We see this kind of problem happening all the time. Unfortunately, Ecos Consulting, the company behind the 80 Plus certification, tests power supplies at 23° C, which is an unrealistic temperature. We test power supplies between 45° C and 50° C, which is a more realistic scenario, and since efficiency drops with temperature, we usually get lower efficiency numbers than those published by the 80 Plus certification. Because of this issue, we consider our numbers more realistic than those provided by manufacturers and by the 80 Plus certification.

Voltages were inside a tighter 3% tolerance during tests one, two, and three. The +5 V output got out of this tighter tolerance during the tests four and five, and the +3.3 V output got out of this tighter range during test five. They were, however, still inside the proper range.

Noise and ripple levels were always very low. Below you can see the results for the power supply outputs during test number five. The maximums allowed are 120 mV for +12 V and -12 V and 50 mV for +5 V and +3.3 V. All values are peak-to-peak figures.

Figure 18: +12VA input from load tester during test five at 698.8 W (38.2 mV)

Figure 19: +12VB input from load tester during test five at 698.8 W (35.6 mV)

Figure 20: +5V rail during test five at 698.8 W (27.6 mV)

Figure 21: +3.3 V rail during test five at 698.8 W (25.6 mV)

Let’s see if we can pull even more from the Cougar GX 700 W.

[nextpage title=”Overload Tests”]

Below you can see the maximum we could pull from this power supply. Here we were limited by our equipment, which can only pull up to 1,000 W from the power supply. Therefore, the Cougar GX 700 W may be able to deliver even more than that. During this test, noise level at +5 V was above the maximum allowed at 54.6 mV and the noise level at +3.3 V was touching the limit at 48.2 mV, and +5 V, +3.3 V and +5VSB voltages were lower than the minimum allowed, clearly showing that this unit had already reach its limits on this outputs.

Input	Overload Test
+12VA	33 A (396 W)
+12VB	3 3 A (396 W)
+5V	23 A (115 W)
+3.3 V	22 A (72.6 W)
+5VSB	3 A (15 W)
-12 V	0.5 A (6 W)
Total	971.4 W
% Max Load	138.8%
Room Temp.	44.4° C
PSU Temp.	39.4° C
AC Power	1,239 W
Efficiency	78.4%
AC Voltage	99.9 V
Power Factor	0.998

[nextpage title=”Main Specifications”]

The Cougar GX 700 W power supply specs include:

• Nominal labeled power: 700 W
• Measured maximum power: 971.4 W at 44.4° C (limited by our equipment)
• Labeled efficiency: Between 89% and 93% at 230 V, 80 Plus Gold certification
• Measured efficiency: Between 86% and 88.5% at 115 V (nominal, see complete results for actual voltage)
• Active PFC: Yes
• Modular Cabling System: Yes, partial
• Motherboard Power Connectors: One 20/24-pin connector, three ATX12V connector (two of them forming an EPS12V connector), and one EPS12V connector (all permanently attached to the power supply)
• Video Card Power Connectors: One cable with one six-pin connector permanently attached to the power supply, one cable with one six/eight-pin connector permanently attached to the power supply, and two cables with one six/eight-pin connector each on the modular cabling system, with the modular cabling system allowing two additional cables
• SATA Power Connectors: Nine on three cables (modular cabling system)
• Peripheral Power Connectors: Six on three cables (modular cabling system)
• Floppy Disk Drive Power Connectors: One, if the included adapter is used
• Protections: Over voltage (OVP), under voltage (UVP), over power (OPP), over temperature (OTP), over current (OCP), and short-circuit (SCP)
• Warranty: Five years
• Real Manufacturer: HEC/Compucase
• More Information: https://www.cougar-world.de
• Average price in the US: This product isn’t sold in the USA

[nextpage title=”Conclusions”]

The only “problem” we see with the Cougar GX 700 W is that it can’t deliver the efficiency promised by the manufacturer under real-world conditions. This may due to several different reasons, and the most commons are:

• The tests for obtaining the 80 Plus certification are conducted at a room temperature of only 23° C, which is an unrealistic value, while we test power supplies between 45° C and 50° C, and efficiency drops with temperature.
• Being a German company, Cougar tests their power supplies at 230 V, while we, being based in the United States, test power supplies at 115 V (efficiency is higher at 230 V)
• The manufacturer conducted their internal tests and sent to the 80 Plus certification process pre-production samples, but mass production power supplies may not maintain the same efficiency numbers as pre-production samples.

Is Cougar GX 700 W a bad power supply? Not at all. It can deliver its labeled power at high temperatures (in fact we could pull almost 1,000 W from it), it has a terrific number of connectors, the cables are very long, voltages were always inside the appropriate numbers, noise and ripple levels were always very low, and efficiency, though not at 80 Plus Gold levels, was very high (between 86% and 88.5%).

So, if you understand that this is a good 80 Plus Silver power supply, you can buy it without fear. Also, if you live in a country with a 230 V power grid, you should be able to get higher efficiency than we did.