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[nextpage title=”Introduction”]
The Corsair GS power supply series is comprised of 500 W, 600 W, 700 W, and 800 W models, with either the standard 80 Plus certification or with the 80 Plus Bronze certification, except for the 500 W model, which is available only with the standard 80 Plus certification. Let’s see if it is a good product.
By the way, we think it is very confusing to have two different power supplies with the same name. We think Corsair should have used a different name for the models with the 80 Plus Bronze certification.
The Corsair GS500 is manufactured by CWT, using the same platform as the Corsair CX series, the Enermax NAXN80+ series, the Enermax NAXN82+ series, and the LEPA B series.
Figure 1: Corsair GS500 power supply
Figure 2: Corsair GS500 power supply
The Corsair GS500 is 6.3” (160 mm) deep, using a 140 mm ball-bearing fan on its bottom (Yate Loon D14BH-12). This is an improvement over other models based on the same platform, which use a 120 mm sleeve-bearing fan. The fan glows blue when the power supply is turned on, but you can turn the LEDs off through a button located at the power supply rear panel.
The reviewed power supply doesn’t have a modular cabling system. All cables are protected with nylon sleeves that come from inside the unit. This power supply comes with the following cables:
- Main motherboard cable with a 20/24-pin connector, 21.6” (55 cm) long
- One cable with two ATX12V connectors that together form an EPS12V connector, 21.2” (54 cm) long
- Two cables, each with one six/eight-pin connector for video cards, 22.8” (58 cm) long
- Two cables, each with three SATA power connectors, 15.7” (40 cm) to the first connector, 5.9” (15 cm) between connectors
- One cable with four standard peripheral power connectors and one floppy disk drive power connector, 15.7” (40 cm) to the first connector, 5.9” (15 cm) between connectors
All wires are 18 AWG, which is the minimum recommended gauge. The number of connectors is outstanding for a 500 W power supply, allowing you to install a high-end video card that requires two auxiliary power connectors without the need for adapters.
Figure 3: Cables
Let’s now take an in-depth look inside this power supply.
[nextpage title=”A Look Inside the Corsair GS500″]
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 4: Top view
Figure 5: Front quarter view
Figure 6: Rear quarter view
Figure 7: 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, with one X capacitor and two Y capacitors more than the minimum required.
Figure 8: Transient filtering stage (part 1)
Figure 9: Transient filtering stage (part 2)
On the next page, we will have a more detailed discussion about the components used in the Corsair GS500.
[nextpage title=”Primary Analysis”]
On this page we will take an in-depth look at the primary stage of the Corsair GS500. For a better understanding, please read our “Anatomy of Switching Power Supplies” tutorial.
This power supply uses one GBU1006 rectifying bridge, which is attached to a heatsink that is connected to the heatsink of the active PFC transistors. This bridge supports up to 10 A at 100° C. So, 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. 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 10: Rectifying bridge
The active PFC circuit uses two MDF18N50 MOSFETs, each supporting up to 18 A at 25° C or 11 A at 100° C in continuous mode (see the difference temperature makes) or 72 A at 25° C in pulse mode. These transistors present a maximum 270 mΩ 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.
Figure 11: Active PFC transistors and diode
The output of the active PFC circuit is filtered by one 330 µF x 400 V electrolytic capacitor, from Samxon, labeled at 85° C.
In the switching section, another two TK13A50DA MOSFETs are employed using the traditional two-transistor forward configuration. Each transistor supports up to 12.5 A at 25° C in continuous mode or up to 50 A at 25° in pulse mode, with a maximum RDS(on) of 470 mΩ. Unfortunately, the manufacturer for these transistors doesn’t publish the current limits at 100° C.
Figure 12: Switching transistors
The primary is managed by the famous CM6800 active PFC/PWM combo controller.
Figure 13: Active PFC/PWM combo controller
Let’s now take a look at the secondary of this power supply.
[nextpage title=”Secondary Analysis”]
The Corsair GS500 uses a regular design in its secondary, with Schottky rectifiers.
The maximum theoretical current each line can deliver is given by the formula I / (1 – D) where D is the duty cycle used and I is the maximum current supported by the rectifying diode. As an exercise, we can assume a duty cycle of 30 percent.
The +12 V output uses four Schottky rectifiers, two SBR30A60CT (30 A, 15 A per internal diode at 110° C, 0.60 V maximum voltage drop) for the direct rectification and two SBR40U60CT (40 A, 20 A per internal diode at 25° C, 0.60 V maximum voltage drop) for the “freewheeling” part of the rectification. This gives us a maximum theoretical current of 43 A or 514 W for the +12 V output.
The +5 V output uses two STPS3045CT Schottky rectifiers (30 A, 15 A per internal diode at 155° C, 0.84 V maximum voltage drop). This gives us a maximum theoretical current of 43 A or 214 W for the +5 V output.
The +3.3 V output uses one STPS4045CW Schottky rectifier (40 A, 20 A per internal diode at 140° C, 0.94 V maximum voltage drop). This gives us a maximum theoretical current of 29 A or 94 W for the +3.3 V output.
Figure 14: The +12 V, +5 V, and +3.3 V rectifiers
This power supply uses an ST9S429 monitoring integrated circuit, which apparently is a rebranded S3515. This chip supports over voltage (OVP), under voltage (UVP), and over current (OCP) protections. Even though this chip provides two +12 V over current channels, the manufacturer decided to configure this unit as a single-channel model.
Figure 15: Monitoring circuit
The electrolytic capacitors that filter the outputs are from Teapo and Samxon and labeled at 105° C, as usual.
[nextpage title=”Power Distribution”]
In Figure 16, you can see the power supply label containing all the power specs.
Figure 16: Power supply label
As you can see, this unit has a single +12 V rail, so there is not much to talk about here.
How much power can this unit really deliver? Let’s find out.
[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, both inputs were connected to the power supply’s single +12 V rail. (The power supply’s EPS12V connector was installed on the +12VB input of the load tester.)
| Input | Test 1 | Test 2 | Test 3 | Test 4 | Test 5 |
| +12VA | 3.5 A (42 W) | 7 A (10.5 W) | 10.5 A (126 W) | 14 A (168 W) | 17.5 A (210 W) |
| +12VB | 3.5 A (42 W) | 7 A (10.5 W) | 10.5 A (126 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 | 102.9 W | 194.3 W | 295.9 W | 396.8 W | 501.8 W |
| % Max Load | 20.6% | 38.9% | 59.2% | 79.4% | 100.4% |
| Room Temp. | 44.8° C | 46.9° C | 47.6° C | 48.6° C | 45.6° C |
| PSU Temp. | 44.8° C | 48.3° C | 48.5° C | 48.9° C | 49.8° C |
| Voltage Regulation | Pass | Pass | Pass | Pass | Pass |
| Ripple and Noise | Pass | Pass | Pass | Pass | Pass |
| AC Power | 123.7 W | 227.3 W | 348.8 W | 475.0 W | 613.1 W |
| Efficiency | 83.2% | 85.5% | 84.8% | 83.5% | 81.8% |
| AC Voltage | 117.3 V | 115.6 V | 114.6 V | 113.1 V | 111.5 V |
| Power Factor | 0.982 | 0.992 | 0.996 | 0.997 | 0.998 |
| Final Result | Pass | Pass | Pass | Pass | Pass |
The Corsair GS500 graduated from our tests with honors. It presented efficiency between 81.8% and 85.5%, which is outstanding for a unit that only has the standard 80 Plus certification. In fact, it presented efficiency higher than a few units with the 80 Plus Bronze certification that we’ve tested. Some units with the 80 Plus Bronze certification fail to provide efficiency close to 82% at full load under high temperatures.
All voltages were closer to their nominal values during all tests (3% voltage regulation), making the GS500 a “flawless” power supply. 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.
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 Corsair GS500 provided extremely low ripple and noise levels, making it a “flawless” unit here as well.
| Input | Test 1 | Test 2 | Test 3 | Test 4 | Test 5 |
| +12VA | 10.0 mV | 9.4 mV | 10.4 mV | 13.8 mV | 32.6 mV |
| +12VB | 10.6 mV | 9.4 mV | 11.8 mV | 14.2 mV | 33.2 mV |
| +5 V | 7.8 mV | 8.4 mV | 9.8 mV | 11.4 mV | 15.6 mV |
| +3.3 V | 7.4 mV | 10.0 mV | 12.6 mV | 14.2 mV | 18.2 mV |
| +5VSB | 10.8 mV | 13.0 mV | 15.6 mV | 19.4 mV | 23.6 mV |
| -12 V | 17.2 mV | 17.2 mV | 20.2 mV | 23.0 mV | 26.4 mV |
Below you can see the waveforms of the outputs during test five.
Figure 17: +12VA input from load tester during test five at 501.8 W (32.6 mV)
Figure 18: +12VB input from load tester during test five at 501.8 W (33.2 mV)
Figure 19: +5V rail during test five at 501.8 W (15.6 mV)
Figure 20: +3.3 V rail during test five at 501.8 W (18.2 mV)
[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, as it shut down when we tried to pull more than listed in the table below. However, noise and ripple levels were way above the maximum allowed (above 300 mV), and voltages were way below the minimum allowed (e.g., +11.12 V), showing that the power supply had already reached its limit.
| Input | Overload Test |
| +12VA | 20 A (240 W) |
| +12VB | 20 A (240 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 | 578.8 W |
| % Max Load | 115.8% |
| Room Temp. | 43.5° C |
| PSU Temp. | 50.5° C |
| AC Power | 740.0 W |
| Efficiency | 78.2% |
| AC Voltage | 110.6 V |
| Power Factor | 0.998 |
[nextpage title=”Main Specifications”]
The main specifications for the Corsair GS500 power supply include:
- Standards: ATX12V 2.3 and EPS12V 2.91
- Nominal labeled power: 500 W at 40° C
- Measured maximum power: 578.8 W at 43.5° C
- Labeled efficiency: 80% minimum, 80 Plus standard certification
- Measured efficiency: Between 81.8% and 85.5%, 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 two cables
- SATA Power Connectors: Six on two cables
- Peripheral Power Connectors: Four on one cable
- Floppy Disk Drive Power Connectors: One
- Protections (as listed by the manufacturer): Over voltage (OVP), under voltage (UVP), over current (OCP), over power (OPP), and short-circuit (SCP)
- Are the above protections really available? Yes.
- Warranty: Three years
- More Information: https://www.corsair.com
- Average Price in the U.S.*: USD 80.00
* Researched at Newegg.com on the day we published this review.
[nextpage title=”Conclusions”]
The Corsair GS500 is a flawless power supply. It has superb
voltage regulation, with all its voltages within 3% of their nominal values, extremely low noise and ripple levels, and efficiency between 81.8% and 85.5%, which could make this unit be certified as 80 Plus Bronze. In fact, we’ve seen units with worse efficiency being certified as 80 Plus Bronze, so definitely Corsair decided to play it safe, which is what we think all manufacturers should do.
The only problem with this power supply is its price, as there are units with higher wattages with the 80 Plus Bronze certification being sold for the same price or less, such as the LEPA B650 (also USD 80) and the Rosewill HIVE 550 W (USD 70).
In summary, the Corsair GS500 is a technically outstanding power supply that you won’t regret buying, but it is too expensive, and the savvy user may want to consider another option.