[nextpage title=”Introduction”]
Cougar has released a power supply series with the 80 Plus Gold certification, called GX-S, with 400 W, 500 W, and 600 W models. They have two +12 V rails and don’t come with a modular cabling system. Let’s see if the 500 W version, also known as “CGR G2-500,” is worth buying.
Cougar is a brand that belongs to HEC/Compucase, but this power supply is manufactured by Andyson.
Figure 1: Cougar GX-S 500 W power supply
Figure 2: Cougar GX-S 500 W power supply
The Cougar GX-S 500 W is only 5.5” (140 mm) deep. It uses a 120 mm sleeve-bearing fan on its bottom (Cougar CF-V 12SB-P, which actually is a rebranded Power Logic PLA12025S12L-4).
Figure 3: Fan
This power supply doesn’t have a modular cabling system. It comes with the following cables:
- Main motherboard cable with a 20/24-pin connector, 20.5” (52 cm) long
- One cable with two ATX12V connectors that together form an EPS12V connector, 23.6” (60 cm) long
- One cable with two six/eight-pin connectors for video cards, 20.5” (52 cm) to the first connector, 5.1” (13 cm) between connectors
- One cable with three SATA power connectors, 18.5” (47 cm) to the first connector, 5.1” (13 cm) between connectors
- One cable with two SATA and one peripheral power connectors, 16.1” (41 cm) to the first connector, 5.1” (13 cm) between connectors
- One cable with one SATA, two peripheral, and one floppy disk drive power connectors, 16.1” (41 cm) to the first connector, 5.1” (13 cm) between connectors
The main motherboard cable and the ATX12V/EPS12V cables use thicker, 16 AWG wires. The other cables use 18 AWG wires, which is the minimum recommended gauge.
The number of connectors is very good for a 500 W power supply.
Figure 4: Cables
Let’s now take an in-depth look inside this power supply.[nextpage title=”A Look Inside the Cougar GX-S 500 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.
On this page we will have an overall look, and then in the following pages we will discuss in detail the quality and ratings of the components used.
Figure 5: Top view
Figure 6: Front quarter view
Figure 7: Rear quarter view
Figure 8: The 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 the transient filtering stage, this power supply is flawless.
Figure 9: Transient filtering stage (part 1)
Figure 10: Transient filtering stage (part 2)
On the next page, we will have a more detailed discussion about the components used in the Cougar GX-S 500 W.
[nextpage title=”Primary Analysis”]
On this page, we will take an in-depth look at the primary stage of the Cougar GX-S 500 W. For a better understanding, please read our “Anatomy of Switching Power Supplies” tutorial.
This power supply uses one BU1006A rectifying bridge, which is attached to the same heatsink as the active PFC and switching transistors. This bridge supports up to 10 A at 90° C. In theory, you would be able to pull up to 1,150 W from a 115 V power grid. Assuming 80% efficiency, the bridge would allow this unit to deliver up to 920 W without burning itself out (or 1,035 W at 90% efficiency). Of course, we are only talking about this particular component. The real limit will depend on all the components combined in this power supply.
Figure 11: Rectifying bridge
The active PFC circuit uses two P22N60E MOSFETs, each one supporting up to 22 A at 25° C or 13.8 A at 100° C in continuous mode (note the difference temperature makes), or 66 A at 25° C in pulse mode. These transistors pre
sent a 165 mΩ maximum resistance when turned on, a characteristic called RDS(on). The lower the number the better, meaning that the transistor will waste less power, and the power supply will have a higher efficiency.
The active PFC circuit is controlled by a CM6502 integrated circuit.
Figure 12: Active PFC controller
The output of the active PFC circuit is filtered by a 390 μF x 400 V Japanese electrolytic capacitor, from Hitachi, labeled at 85° C.
Figure 13: Capacitor
In the switching section, two STP28NM50N MOSFETs are employed using a resonant configuration. Each transistor supports up to 21 A at 25° C or 13 A at 100° C in continuous mode or up to 84 A at 25° C in pulse mode, with a maximum RDS(on) of 158 mΩ.
Figure 14: The switching transistors, the active PFC diode, and the active PFC transistors
The switching transistors are controlled by a CM6901 resonant controller, which was placed in the secondary of the power supply.
Figure 15: Resonant controller and active PFC controller
Let’s now take a look at the secondary of this power supply.[nextpage title=”Secondary Analysis”]
As one would expect in a high-efficiency power supply, the Cougar GX-S 500 W uses a synchronous design, where the Schottky rectifiers are replaced with MOSFETs. Also, the reviewed product uses a DC-DC design in its secondary. This means that the power supply is basically a +12 V unit, with the +5 V and +3.3 V outputs produced by two smaller power supplies connected to the main +12 V rail. Both designs are used to increase efficiency.
The +12 V output uses four IRFB7446 MOSFETs, each one supporting up to 120 A at 25° C or 87 A at 100° C in continuous mode, or up to 492 A at 25° C in pulse mode, with a maximum RDS(on) of 3.3 mΩ.
Figure 16: The +12 V transistors
As explained, the +5 V and +3.3 V outputs are produced by two DC-DC converters, each one located on a daughterboard soldered to the main printed circuit board. Each converter is controlled by an APW7073 integrated circuit and uses four STD85N3L MOSFETs, each one supporting up to 80 A at 25° C or 55 A at 100° C in continuous mode and up to 320 A at 25° C in pulse mode, with a maximum RDS(on) of 5 mΩ.
Figure 17: One of the DC-DC converters
Figure 18: One of the DC-DC converters
The outputs of the power supply are monitored by a PS223 integrated circuit, which supports over voltage (OVP), under voltage (UVP), and over current (OCP) protections. There are four OCP channels, one for +3.3 V, one for +5 V, and two for +12 V, correctly matching the number of +12 V rails advertised by the manufacturer.
Figure 19: Monitoring circuit
This power supply uses a mix of solid and electrolytic capacitors in its secondary. The electrolytic capacitors are from Teapo and labeled at 105° C, as usual.
Figure 20: Capacitors
[nextpage title=”The +5VSB Power Supply”]
The +5VSB (a.k.a. standby) power supply is independent of the main power supply, since it is on continuously.
The +5VSB power supply uses an STR-A6062H integrated circuit, which incorporates the PWM controller and the switching transistor into a single chip.
Figure 21: The +5VSB integrated circuit with an integrated switching transistor
The rectification of the +5VSB output is performed by an SBL1060CTW Schottky rectifier present on the solder side of the printed circuit board. This component supports up to 10 A (5 A per internal diode at 95° C, 0.70 V maximum voltage drop).
Figure 22: The +5VSB rectifier
[nextpage title=”Power Distribution”]
In Figure 23, you can see the power supply label containing all the power specs.
Figure 23: Power supply label
As you can see, the manufacturer says this unit has two
+12 V rails. Inside the unit, we could check that the monitoring circuit really has two +12 V over current protection (OCP) channels, and we could clearly see one shunt (current sensor) per +12 V rail. See Figure 24. Click here for more information on this subject.
Figure 24: The +12 V shunts
The two rails are distributed like this:
- +12V1: All cables but the ATX12V/EPS12V
- +12V2: The ATX12V/EPS12 cable
This is the typical configuration used on power supplies with two +12 V rails.
Let’s find out how much power this unit can deliver.
[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 powers listed for each test, you may find a different value than what is posted under “Total” below. Since each output can have a slight variation (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 rail, while the +12VB input was connected to the power supply +12V2 rail (EPS12V connector).
| Input | Test 1 | Test 2 | Test 3 | Test 4 | Test 5 |
| +12VA | 3.5 A (42 W) | 7.5 A (90 W) | 10.5 A (14 W) | 14 A (168 W) | 17.5 A (210 W) |
| +12VB | 3.5 A (42 W) | 7 A (84 W) | 10.5 A (14 W) | 14 A (168 W) | 17 A (204 W) |
| +5 V | 1 A (5 W) | 2 A (10 W) | 4 A (20 W) | 6 A (30 W) | 8 A (40 W) |
| +3.3 V | 1 A (3.3 W) | 2 A (6.6 W) | 4 A (13.2 W) | 6 A (19.8 W) | 8 A (26.4 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 | 104.7 W | 210.4 W | 302.9 W | 406.4 W | 501.4 W |
| % Max Load | 20.9% | 42.1% | 60.6% | 81.3% | 100.3% |
| Room Temp. | 47.8° C | 46.0° C | 46.3° C | 47.8° C | 49.4° C |
| PSU Temp. | 50.9° C | 50.2° C | 49.8° C | 50.6° C | 51.9° C |
| Voltage Regulation | Failed on -12 V | Pass | Pass | Pass | Pass |
| Ripple and Noise | Pass | Pass | Pass | Pass | Pass |
| AC Power | 119.9 W | 233.2 W | 335.6 W | 459.1 W | 574.4 W |
| Efficiency | 87.3% | 90.2% | 90.3% | 88.5% | 87.3% |
| AC Voltage | 118.6 V | 117.5 V | 116.4 V | 114.9 V | 113.7 V |
| Power Factor | 0.962 | 0.975 | 0.983 | 0.988 | 0.989 |
| Final Result | Pass | Pass | Pass | Pass | Pass |
The 80 Plus Gold certification promises efficiency of at least 87% under light (i.e., 20%) load, 90% under typical (i.e., 50%) load, and 87% under full (i.e., 100%) load. The Cougar GX-S 500 W was able to match these numbers at high temperatures, which is excellent.
Let’s discuss voltage regulation on the next page.
[nextpage title=”Voltage Regulation Tests”]
The ATX12V specification states that positive voltages must be within 5% of their nominal values, and negative voltages must be within 10% of their nominal values. We consider a power supply as “flawless” if it shows voltages within 3% of its nominal values. In the table below, you can see the power supply voltages during our tests and, in the following table, the deviation, in percentage, of their nominal values.
The Cougar GX-S 500 W presented excellent voltage regulation for its positive outputs, all within 3% of their nominal values. The -12 V output, however, was touching the allowed limit during test one.
| Input | Test 1 | Test 2 | Test 3 | Test 4 | Test 5 |
| +12VA | +12.28 V | +12.24 V | +12.18 V | +12.14 V | +12.08 V |
| +12VB | +12.29 V | +12.26 V | +12.28 V | +12.20 V | +12.15 V |
| +5 V | +5.11 V | +5.10 V | +5.08 V | +5.05 V | +5.03 V |
| +3.3 V | +3.36 V | +3.34 V | +3.30 V | +3.26 V | +3.24 V |
| +5VSB | +4.95 V | +4.95 V | +4.91 V | +4.88 V | +4.85 V |
| -12 V | -10.85 V | -10.96 V | -11.18 V | -11.33 V | -11.47 V |
| Input | Test 1 | Test 2 | Test 3 | Test 4 | Test 5 |
| +12VA | 2.33% | 2.00% | 1.50% | 1.17% | 0.67% |
| +12VB | 2.42% | 2.17% | 2.33% | 1.67% | 1.25% |
| +5 V | 2.20% | 2.00% | 1.60% | 1.00% | 0.60% |
| +3.3 V | 1.82% | 1.21% | 0.00% | -1.21% | -1.82% |
| +5VSB | -1.00% | -1.00% | -1.80% | -2.40% | -3.00% |
| -12 V | 9.58% | 8.67% | 6.83% | 5.58% | 4.42% |
Let’s discuss the ripple and noise levels on the next page.
[nextpage title=”Ripple and Noise Tests”]
Voltages at the power supply outputs must be as “clean” as possible, with no noise or oscillation (also known as “ripple”). The maximum ripple and noise levels allowed are 120 mV for +12 V and -12 V outputs, and 50 mV for +5 V, +3.3 V and +5VSB outputs. All values are peak-to-peak figures. We consider a power supply as being top-notch if it can produce half or less of the maximum allowed ripple and noise levels.
The Cougar GX-S 500 W provided low ripple and noise levels, as you can see below.
| Input | Test 1 | Test 2 | Test 3 | Test 4 | Test 5 |
| +12VA | 44.8 mV | 44.2 mV | 48.0 mV | 49.4 mV | 50.4 mV |
| +12VB | 44.2 mV | 44.2 mV | 48.2 mV | 48.2 mV | 48.4 mV |
| +5 V | 9.6 mV | 11.2 mV | 13.2 mV | 15.2 mV | 18.8 mV |
| +3.3 V | 9.8 mV | 10.8 mV | 13.8 mV | 17.2 mV | 19.4 mV |
| +5VSB | 9.4 mV | 10.4 mV | 12.0 mV | 15.4 mV | 18.8 mV |
| -12 V | 52.4 mV | 51.6 mV | 49.4 mV | 55.4 mV | 49.6 mV |
Below you can see the waveforms of the outputs during test five.
Figure 25: +12VA input from load tester during test five at 501.4 W (50.4 mV)
Figure 26: +12VB input from load tester during test five at 501.4 W (48.4 mV)
Figure 27: +5V rail during test five at 501.4 W (18.8 mV)
Figure 28: +3.3 V rail during test five at 501.4 W (19.4 mV)
Let’s see if we can pull more than 500 W from this unit.[nextpage title=”Overload Tests”]
Below you can see the maximum we could pull from this power supply. The objective of this test is to see if the power supply has its protection circuits working properly. This unit passed this test, since it shut down when we tried to pull more than what is listed below. During this test, noise and ripple levels were still extremely low and voltages were within 3% of their nominal values.
| Input | Overload Test |
| +12VA | 24 A (288 W) |
| +12VB | 24 A (288 W) |
| +5 V | 10 A (50 W) |
| +3.3 V | 10 A (33 W) |
| +5VSB | 3 A (15 W) |
| -12 V | 0.5 A (6 W) |
| Total | 678.4 W |
| % Max Load | 135.7% |
| Room Temp. | 48.0° C |
| PSU Temp. | 51.3° C |
| AC Power | 804 W |
| Efficiency | 84.4% |
| AC Voltage | 111.5 V |
| Power Factor | 0.991 |
[nextpage title=”Main Specifications”]
The main specifications for the Cougar GX-S 500 W power supply include:
- Standards: NA
- Nominal labeled power: 500 W at 40° C
- Measured maximum power: 678.4 W at 48.0° C
- Labeled efficiency: Up to 93%, 80 Plus Gold certification (87% at light/20% load, 90% at typical/50% load, and 87% at full/100% load)
- Measured efficiency: Between 87.3% and 90.3% at 115 V (nominal, see complete results for actual voltage)
- Active PFC: Yes
- Modular Cabling System: No
- Motherboard Power Connectors: One 20/24-pin connector and two ATX12V connectors that together form an EPS12V connector
- Video Card Power Connectors: Two six/eight-pin connectors on the same cable
- SATA Power Connectors: Six on three cables
- Peripheral Power Connectors: Three on two cables
- Floppy Disk Drive Power Connectors: One
- Protections (as listed by the manufacturer): Over voltage (OVP), under voltage (UVP), over current (OCP), over power (OPP), over temperature (OTP), and short-circuit (SCP) protections
- Are the above protections really available? Yes.
- Warranty: Three years
- Real Manufacturer: Andyson
- More Information: https://www.cougar-world.com
- MSRP in the U.S.: USD 110.00
[nextpage title=”Conclusions”]
The Cougar GX-S 500 W is a good 500 W power supply with the 80 Plus Gold certification targeted to the mainstream user. During our tests, it could really deliver efficiency according to this certification at high temperatures, which is great. Positive voltages were always within 3% of their nominal values and noise and ripple levels were always below half of the maximum allowed.
On the negative side, the -12 V output presented a voltage outside the allowed range under light load.
The success of this power supply will depend on its price. At USD 110, the manufacturer’s suggested price, it faces a tough competition from the Rosewill FORTRESS-650 (USD 95, 80 Plus Platinum and 650 W labeled wattage), the Rosewill CAPSTONE-550M (USD 100, 80 Plus Gold, 550 W labeled wattage, and modular cabling system), and the FSP Aurum Gold 500 W (USD 90).
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