[nextpage title=”Introduction”]

The new Gaming Series (GS) from Corsair is an entry-level power supply series, with 600 W, 700 W, and 800 W models, featuring  a fan with three different color choices, single +12 V rail, and standard 80 Plus certification. Let’s see if the 800 W model is a good pick for the average user.

Corsair GS series power supplies are manufactured by CWT ( “PSH II xy-ZZ REV: 05” printed circuit board and a sticker saying “II 800,” probably meaning that the GS800 is actually a rebranded CWT PSH II 800 power supply).

Corsair GS800 power supplyFigure 1: Corsair GS800 power supply

Corsair GS800 power supplyFigure 2: Corsair GS800 power supply

The Corsair GS800 is 6.3” (160 mm) deep and comes with a 140 mm dual ball-bearing fan on its bottom (Yate Loon D14BH-12, 2,800 rpm, 140 cfm, 48.5 dB). This fan comes with three different sets of LEDs, red, white, and blue, and you can choose the color the fan will glow through a button located at the rear side of the power supply, next to the on/off switch.

The reviewed product doesn’t have a modular cabling system, and it comes with the following cables:

  • Main motherboard cable with a 20/24-pin connector, 23.6” (60 cm) long
  • One cable with two ATX12V connectors each that together form an EPS12V connector, 24” (61 cm) long
  • Four cables with one six/eight-pin connector for video cards each, 24” (61 cm) long
  • Two cables with four SATA power connectors each, 15.3” (39 cm) to the first connector, 5.9” (15 cm) between connectors
  • Two cables with four standard peripheral power connectors and one floppy disk drive power connector each, 15” (38 cm) to the first connector, 5.9” (15 cm) between connectors

All wires are 18 AWG, which is the minimum recommended gauge, except the wires on the main motherboard cable, which are thicker (16 AWG).

The cable configuration is very good for a 800 W product, allowing you to have up to two high-end video cards without the need of adapters.

Corsair GS800 power supplyFigure 3: Cables

Let’s now take an in-depth look inside this power supply.

[nextpage title=”A Look Inside The Corsair GS800″]

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.

Corsair GS800 power supplyFigure 4: Top view

Corsair GS800 power supplyFigure 5: Rear quarter view

Corsair GS800 power supplyFigure 6: Front quarter view

Corsair GS800 power supplyFigure 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. 

This power supply has all the minimum required components plus two additional Y capacitors, one additional X capacitor, and one X capacitor after the rectifying bridge.

Corsair GS800 power supplyFigure 8: Transient filtering stage (part 1)

Corsair GS800 power supplyFigure 9: Transient filtering stage (part 2)

In the next page we will have a more detailed discussion about the components used in the Corsair GS800.

[nextpage title=”Primary Analysis”]

On this page we will take an in-depth look at the primary stage of the Corsair GS800 For a better understanding, please read our Anatomy of Switching Power Supplies tutorial.

This power supply use one GBU1506 rectifying bridge, which is attached to the same heatsink where the active PFC transistors are located. This bridge supports up to 15 A at 55° C so, in theory, you would be able to pull up to 1,725 W from a 115 V power grid. Assuming 80% efficiency, the bridge would allow this unit to deliver up to 1,380 W without burning itself out. Of course, we are only talking about this component, and the real limit will depend on all the other components in this power supply.

Corsair GS800 power supplyFigure 10: Rectifying bridge

The active PFC circuit uses two TK20J60U MOSFETs, each one capable of delivering up to 20 A at 25° C in continuous mode (unfortunately the manufacturer doesn’t publish the current limit at 100° C), or up to 40 A in pulse mode at 25° C. These transistors present a 165 m&Om
ega; 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.

Corsair GS800 power supplyFigure 11: Active PFC transistors

The output of the active PFC circuit is filtered by a capacitor from Samxon, labeled at 105° C.

In the switching section, two SPA16N50C3 MOSFETs are used, installed in the two-transistor forward configuration. These transistors support up to 16 A at 25° C or up to 10 A at 100° C in continuous mode, or up to 48 A at 25° C in pulse mode, with an RDS(on) of 280 mΩ.

Corsair GS800 power supplyFigure 12: Switching transistors

The primary is controlled by the famous CM6800 active PFC/PWM combo controller.

Corsair GS800 power supplyFigure 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 comes with eight Schottky rectifiers attached to its secondary heatsink.

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. Just as an exercise, we can assume a typical duty cycle of 30%.

The +12 V output is generated using six STPS3045CT Schottky rectifiers, three in charge of the direct rectification and three used in the "freewheeling" part of the rectification. Each rectifier supports up to 30 A (15 A per internal diode at 155° C, maximum voltage drop of 0.84 V), giving us a maximum theoretical current of 129 A or 1,543 W for the +12 V output.

The +5 V output is generated using one STPS3045CW Schottky rectifier, which supports up to 30 A (15 A per internal diode at 155° C, maximum voltage drop of 0.84 V), giving us a maximum theoretical current of 21 A or 107 W for the +5 V output.

The +3.3 V output is generated using another STPS3045CW Schottky rectifier, giving us a maximum theoretical current of 21 A or 71 W for the +3.3 V output.

Corsair GS800 power supplyFigure 14: +3.3 V, +12 V and +5 V rectifiers

The secondary is monitored by a PS229 integrated circuit. Unfortunately there is no technical information available for this component and, therefore, we can’t comment on the protections this power supply really supports.

Corsair GS800 power supplyFigure 15: Monitoring circuit

Some of the electrolytic capacitors of the secondary are Japanese, from Chemi-Con, and some are Taiwanese, from Teapo. Also, there is one solid capacitor.

[nextpage title=”Power Distribution”]

In Figure 16, you can see the power supply label containing all the power specs.

Corsair GS800 power supplyFigure 16: Power supply label

This power supply has a single +12 V rail, so there is not much to talk about here.

Let’s now see if this power supply can really deliver 800 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 how the reviewed unit behaved 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. On 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. Since the reviewed unit has a single +12 V rail, both inputs were connected to the power supply single +12 V rail (+12VB was connected to the power supply EPS12V connector and all other cables were connected to the load tester +12VA input).

Input Test 1 Test 2 Test 3 Test 4 Test 5
+12VA 5.5 A (66 W) 12 A (144 W) 17.5 A (210 W) 23 A (276 W) 29 A (348 W)
+12VB 5.5 A (66 W) 11 A (132 W) 17 A (204 W) 23 A (276 W) 29 A (348 W)
+5V 2 A (10 W) 4 A (20 W) 6 A (6 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 171.9 W 326.0 W 482.5 W 637.5 W 798.4 W
% Max Load 21.5% 40.8% 60.3% 79.7% 99.8%
Room Temp. 46.4° C 46.2° C 47.9° C 46.5° C 48.4° C
PSU Temp. 47.2° C 48.3° C 49.6° C 51.5° C 51.5° C
Voltage Regulation Pass Pass Pass Pass Pass
Ripple and Noise Pass Pass Pass Pass Pass
AC Power 205.6 W 380.5 W 571.0 W 770.0 W 995.0 W
Efficiency 83.6% 85.7% 84.5% 82.8% 80.2%
AC Voltage 114.2 V 112.6 V 111.0 V 109.1 V 105.6 V
Power Factor 0.970 0.987 0.992 0.994 0.995
Final Result Pass Pass Pass Pass Pass

The Corsair GS800 passed with flying colors in our tests.

Efficiency was relatively high for an entry-level product, peaking 85.7%, but at full load it dropped to around 80%.

Voltages were always within 3% of their nominal voltages, meaning that voltage regulation of this power supply is better than required, as the ATX12V specification allows 5% tolerance (10% for -12 V). The only exception was the -12 V output during test five, which exit this tighter tolerance, but was still within 5% of its nominal value.

Noise and ripple levels were always within specs, even though the noise levels at +12 V and +5 V were a little bit higher than we’d like to see to consider a power supply “flawless” (we always like to see power supplies with noise levels below half of their limits). Since this is an entry-level model, we can’t complain. Below you can see the results for the power supply outputs during test number five. The maximum allowed is 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.

Corsair GS800 power supplyFigure 17: +12VA input from load tester during test five at 798.4 W (75.4 mV)

Corsair GS800 power supplyFigure 18: +12VB input from load tester during test five at 798.4 W (68.2 mV)

Corsair GS800 power supplyFigure 19: +5V rail during test five at 798.4 W (31.4 mV)

Corsair GS800 power supplyFigure 20: +3.3 V rail during test five at 798.4 W (10.8 mV)

Let’s see if we can pull even more from the Corsair GS800.

[nextpage title=”Overload Tests”]

Below you can see the maximum we could pull from this power supply. Here we were limited by our load tester, that can pull only up to 1,000 W. Maybe the GS800 can deliver even more than that. However, note how efficiency dropped a lot during this test, showing that this unit has already reached its limit.

Input Overload Test
+12VA 32.5 A (390 W)
+12VB 32.5 A (390 W)
+5V 24 A (120 W)
+3.3 V 24 A (79.2 W)
+5VSB 3 A (15 W)
-12 V 0.5 A (6 W)
Total 997.8 W
% Max Load 124.7%
Room Temp. 42.4° C
PSU Temp. 41.6° C
AC Power 1,345 W
Efficiency 74.2%
AC Voltage 100.4 V
Power Factor 0.996

[nextpage title=”Main Specifications”]

The specs of the Corsair GS800 include:

  • Standards: ATX12V 2.3 and EPS12V 2.91
  • Nominal labeled power: 800 W at 40° C
  • Measured maximum power: 997.8 W at 42.4° C ambient
  • Labeled efficiency: 80% minimum, 80 Plus certification
  • Measured efficiency: Between 80.2% and 85.7% 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 each that together form an EPS12V connector
  • Video Card Power Connectors: Four six/eight-pin connectors on separate cables
  • SATA Power Connectors: Eight on two cables
  • Peripheral Power Connectors: Eight on two cables
  • Floppy Disk Drive Power Connectors: Two on two cables
  • Protections (as listed by the manufacturer): Over voltage (OVP), under voltage (UVP), over power (OPP/OLP), over current (OCP), and short-circuit (SCP) protections
  • Are the above-listed protections really present?: Couldn’t be checked
  • Warranty: Three years
  • Real Manufacturer: CWT
  • More Information: https://www.corsair.com
  • MSRP in the US: USD 120.00

[nextpage title=”Conclusions”]

The new Corsair GS800 is a terrific power supply for its price point, and we highly recommend it if you are looking for an 800 W unit with a good cost/benefit ratio.

Even though it only has the standard 80 Plus certification, we saw efficiency up to 85.7%, and we could pull up to 1,000 W from it (even though under this extreme condition efficiency dropped a lot). Voltages were closer to their nominal values than required (3% voltage regulation), and ripple and noise levels were below the maximum allowed.