[nextpage title=”Introduction”]

We also like to review low-end products from time to time so people with a serious budget restriction can have an idea whether it is worthwhile to buy cheap products or not. Today we are going to take an in-depth look at the eXtreme Power Plus 600 W (RS-600-PCAR-E3) from Cooler Master. Can it really deliver its rated power? Let’s see.

We’ve already reviewed the 400 W (RS-400-PCAR-A3), the 460 W (RS-460-PMSR-A3), the 500 W (RS-500-PCAR-A3), and the 550 W (RS-550-PCAR-E3) models from this same series. The 400 W and the 500 W models were able to deliver their labeled wattages, but both presented very high noise and ripple on their outputs, and the 460 W and the 550 W models weren’t capable of delivering their labeled capacity. Let’s see the fate of this 600 W model.

Models from the eXtreme Power Plus series up to 460 W are manufactured by AcBel Polytech, while models from 500 W and up are manufactured by Seventeam, just like members from an older series called eXtreme Power (without the “Plus”). Our guess is that the "A3" at the end of the part number indicates the first manufacturer, while "E3" indicates the second.

The Cooler Master eXtreme Power Plus 600 W, like the 550 W model and the Spire Jewel Black 650 W, is based on the same platform as the Seventeam ST-500BAZ power supply (already discontinued by the manufacturer). In this review we will check what the differences are among these products.

By the way, like other members from this series, the reviewed unit has the fantastic “As sealed stick was removed, lost or damaged, it shall be out of warranty validity” statement on its label. When will Chinese manufacturers stop using on-line translators and hire someone that can speak English to write their labels?

An interesting thing is that on the power supply label there is no information about the unit’s maximum wattage (the “600” number is printed without the letter “W” after it). This typically happens with low-end units that can’t deliver their labeled wattage. Hum…

Cooler Master eXtreme Power Plus 600 W power supplyFigure 1: Cooler Master eXtreme Power Plus 600 W power supply

Cooler Master eXtreme Power Plus 600 W power supplyFigure 2: Cooler Master eXtreme Power Plus 600 W power supply

The Cooler Master eXtreme Power Plus 600 W is 5 ½” (140 mm) deep, using a 120 mm fan on its bottom. The fan used is a brushless model from ADDA (AD1212US-A71GL).

This unit does not feature an active PFC circuit, as you can see by the presence of a 115 V/230 V switch in Figure 1, but at least it is being based on a more modern design than the outdated half-bridge topology, as we will show.

No modular cabling system is provided and only the main motherboard cables has a nylon protection that comes from inside the power supply housing. All cables use 18 AWG wires, which is the correct gauge to be used and an improvement over the models with lower wattage from this series, which use thinner 20 AWG wires. The cables included are:

  • Main motherboard cable with a 20/24-pin connector, 17 ¾” (45 cm) long
  • One cable with two ATX12V connectors that together form one EPS12V connector, 21 ¼” (54 cm) long
  • Two cables with one six/eight-pin connector for video cards each, 18 1/8” (46 cm) long
  • Two cables with three SATA power connectors each, 18 1/8” (46 cm) to the first connector, 5 7/8” (15 cm) between connectors
  • One cable with three standard peripheral power connectors and one floppy disk drive power connector, 18 1/8” (46 cm) to the first connector, 5 7/8” (15 cm) between connectors

This configuration is identical to the one used on the 550 W version of this power supply, presenting more connectors than the Seventeam ST-500BAZ, the power supply that this model is based on.

Cooler Master eXtreme Power Plus 600 W power supplyFigure 3: Cables

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

[nextpage title=”A Look Inside The eXtreme Power Plus 600 W”]

We decided to disassemble this power supply to see how it looks inside, what design is used, 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. As already explained, this power supply is based on the same project as the Seventeam ST-500BAZ. In the next pages we will spot the differences between the two.

Cooler Master eXtreme Power Plus 600 W power supplyFigure 4: Overall look

Cooler Master eXtreme Power Plus 600 W power supplyFigure 5: Overall look

Cooler Master eXtreme Power Plus 600 W power supplyFigure 6: Overall look

[nextpage title=”Transient Filtering Stage”]

As we have mentioned in other articles and reviews, the first place we like to look when opening a power supply to have 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 one X capacitor, three Y capacitors, one ferrite coil, and one MOV more than the mi
nimum required. Besides having two MOVs squeezed between the two capacitors of the voltage doubler circuit, it has one at the power supply input – all three MOVs can’t be seen on the pictures below.

Cooler Master eXtreme Power Plus 600 W power supplyFigure 7: Transient filtering stage (part 1)

Cooler Master eXtreme Power Plus 600 W power supplyFigure 8: Transient filtering stage (part 2)

[nextpage title=”Primary Analysis”]

On this page we will take an in-depth look at the primary stage of the Cooler Master eXtreme Power Plus 600 W. For a better understanding, please read our Anatomy of Switching Power Supplies tutorial.

This power supply uses two GBU1006 rectifying bridges on its primary, but they are not attached to a heatsink. Each bridge supports up to 10 A at 100° C, so in theory, you would be able to pull up to 2,300 W from the power grid. Assuming 80% efficiency, the bridges would allow this unit to deliver up to 1,840 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. These are the same components found in the Seventeam ST-500BAZ and the 550 W version of the eXtreme Power Plus.

Cooler Master eXtreme Power Plus 600 W power supplyFigure 9: Rectifying bridges

This unit is based on a single-transistor forward topology, which is good to see, since usually low-end units are based on the obsolete half-bridge design. Two 2SK2968 power MOSFETs are connected in parallel on the switching section in order to double the maximum current this section can handle. Each transistor supports up to 10 A at 25° C in continuous mode, or up to 30 A at 25° C in pulse mode, so the switching section can deliver up to 20 A at 25° C. Unfortunately the manufacturer does not provide the current limits at 100° C. These transistors present an RDS(on) of 1.05 Ω, which is insanely high (low efficiency). This number measures the resistance provided by the transistors when they are turned on; the lower this number, the better (higher efficiency). These transistors are a little bit more powerful than ones used in the eXtreme Power Plus 550 W, Seventeam ST-500BAZ, and Spire Jewel Black 650 W – these other power supplies are all based on the same design, but use two 2SK2611 transitors, which have a maximum current of 9 A each.

Cooler Master eXtreme Power Plus 600 W power supplyFigure 10: Switching transistors

The switching transistors are controlled by a TL3842P integrated circuit.

Cooler Master eXtreme Power Plus 600 W power supplyFigure 11: PWM controller

The electrolytic capacitors of the voltage doubler circuit are from Su’scon and labeled at 85° C.

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

[nextpage title=”Secondary Analysis”]

This power supply has five Schottky rectifiers on 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 by two S30D150C Schottky rectifiers connected in parallel, each one capable of handling up to 30 A (15 A per internal diode at 100° C, 0.95 V maximum voltage drop), giving us a maximum theoretical current of 43 A or 514 W for the +12 V output. These are the same components used in the eXtreme Power Plus 550 W, Spire Jewel Black 650 W, and Seventeam ST-500BAZ.

The +5 V output is generated by one SBL6040PT Schottky rectifier, which is capable of handling up to 60 A (30 A per internal diode at 100° C, 0.95 V voltage drop), giving us a maximum theoretical current of 43 A or 214 W. This is the same rectifier used in the eXtreme Power Plus 550 W, Spire Jewel Black 650 W, and Seventeam ST-500BAZ.

The +3.3 V output is generated by two SBL3040PT Schottky rectifiers connected in parallel, each one capable of  handling up to 30 A (15 A per internal diode at 95° C, 0.55 V voltage drop), which gives us a maximum theoretical current of 43 A or 141 W. These are the same components used in the eXtreme Power Plus 550 W, Spire Jewel Black 650 W, and Seventeam ST-500BAZ.

Cooler Master eXtreme Power Plus 600 W power supplyFigure 12: +3.3 V, +5 V and +12 V rectifiers

This power supply uses a WT7510 monitoring integrated circuit, which supports only over voltage (OVP) and under voltage (UVP) protections.

Cooler Master eXtreme Power Plus 600 W power supplyFigure 13: Monitoring circuit

Electrolytic capacitors from the secondary are also from Su’scon and labeled at 105° C.

[nextpage title=”Power Distribution”]

In Figure 14, you can see the power supply label containing all the power specs.

Cooler Master eXtreme Power Plus 600 W power supplyFigure 14: Power supply label

According to the label, this unit has two +12 V rails. Inside the unit the +12 V wires are separat
ed into two different groups connected to individual filtering stages. Although this is a terrific configuration, there is no over current protection monitoring for each rail. The two groups are divided like this:

  • +12V1 (solid yellow wire): Main motherboard cable, SATA power cables, peripheral power cable, and one of the video card power cables
  • +12V2 (yellow with black stripe wire): ATX12V/EPS12V cable and one of the video card power cables

If you are going to install a video card with just one auxiliary power connector, install it to the connector using solid yellow wires. This way you are going to keep the video card separated from the CPU.

Now let’s see if this power supply can really deliver 600 W.

[nextpage title=”Load Tests”]

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

This time we made more detailed tests, starting from 85 W and increasing the load little by little until we could see the maximum amount of power we could extract from the reviewed unit.

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. During this test the +12VA input was connected to the power supply “+12V1” rail, while +12VB was connected to the power supply “+12V2” rail (EPS12V connector).

Input Test 1 Test 2 Test 3 Test 4 Test 5
+12VA 3 A (36 W) 3.5 A (42 W) 4.5 A (54 W) 5.5 A (66 W) 6.25 A (75 W)
+12VB 2.5 A (30 W) 3.25 A (39 W) 4 A (48 W) 5 A (60 W) 6 A (72 W)
+5V 1 A (5 W) 1 A (5 W) 1.5 A (7.5 A) 1.5 A (7.5 A) 2 A (10 W)
+3.3 V 1 A (5 W) 1 A (5 W) 1.5 A (4.95 W) 1.5 A (4.95 W) 2 A (6.6 W)
+5VSB 1 A (5 W) 1 A (5 W) 1 A (5 W) 1 A (5 W) 1 A (5 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 84.0 W 98.6 W 123.5 W 146.8 W 171.5 W
% Max Load 14.0% 16.4% 20.6% 24.5% 28.6%
Room Temp. 45.5° C 44.2° C 41.5° C 40.7° C 40.4° C
PSU Temp. 48.1° C 47.5° C 47.2° C 46.9° C 46.9° C
Voltage Regulation Pass Pass Pass Pass Pass
Ripple and Noise Pass Pass Pass Pass Pass
AC Power 121.3 W 137.1 W 166.1 W 192.9 W 223.4 W
Efficiency 69.2% 71.9% 74.4% 76.1% 76.8%
AC Voltage 112.5 V 111.9 V 111.2 V 110.7 V 110.8 V
Power Factor 0.633 0.644 0.66 0.67 0.684
Final Result Pass Pass Pass Pass Pass
Input Test 6 Test 7 Test 8 Test 9 Test 10
+12VA 7.5 A (90 W) 8.25 A (99 W) 9.25 A (111 W) 10 A (120 W) 11 A (132 W)
+12VB 7 A (84 W) 8 A (96 W) 9 A (108 W) 10 A (120 W) 11 A (132 W)
+5V 2 A (10 W) 2.5 A (12.5 W) 2.5 A (12.5 W) 3 A (15 W) 3 A (15 W)
+3.3 V 2 A (6.6 W) 2.5 A (8.25 W) 2.5 A (8.25 W) 3 A (9.9 W) 3 A (9.9 W)
+5VSB 1 A (5 W) 1 A (5 W) 1 A (5 W) 1 A (5 W) 1 A (5 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 197.3 W 221.8 W 244.8 W 269.3 W 291.7 W
% Max Load 32.9% 37.0% 40.8% 44.9% 48.6%
Room Temp. 41.5° C 42.8° C 44.0° C 43.0° C 43.9° C
PSU Temp. 46.9° C 47.3° C 47.9° C 48.8° C 49.9° C
Voltage Regulation Pass Pass Pass Pass Pass
Ripple and Noise Pass Pass Pass Pass Pass
AC Power 255.4 W 286.4 W 315.5 W 347.4 W 376.6 W
Efficiency 77.3% 77.4% 77.6% 77.5% 77.5%
AC Voltage 110.0 V 109.8 V 108.5 V 108.2 V 108.2 V
Power Factor 0.689 0.699 0.706 0.711 0.715
Final Result Pass Pass Pass Pass Pass

Input Test 11 Test 12 Test 13 Test 14 Test 15
+12VA 12 A (144 W) 13 A (156 W) 14 A (168 W) 15 A (180 W) 16 A (192 W)
+12VB 11.75 A (141 W) 12.75 A (153 W) 13.5 A (162 W) 14.5 A (174 W) 15.5 A (186 W)
+5V 3.5 A (17.5 W) 3.5 A (17.5 W) 4 A (20 W) 4 A (20 W) 4.5 A (22.5 W)
+3.3 V 3.5 A (11.55 W) 3.5 A (11.55 W) 4 A (13.2 W) 4 A (13.2 W) 4.5 A (14.85 W)
+5VSB 1 A (5 W) 1 A (5 W) 1 A (5 W) 1 A (5 W) 1 A (5 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 315.9 W 338.3 W 362.8 W 384.3 W 410.5 W
% Max Load 52.7% 56.4% 60.5% 64.1% 68.4%
Room Temp. 44.3° C 45.7° C 47.4° C 48.6° C 48.8° C
PSU Temp. 50.8° C 51.9° C 53.6° C 45.8° C 42.8° C
Voltage Regulation Pass Pass Pass Pass Pass
Ripple and Noise Pass Pass Pass Pass Pass
AC Power 409.0 W 439.0 W 472.0 W 504.0 W 542.0 W
Efficiency 77.2% 77.1% 76.9% 76.3% 75.7%
AC Voltage 108.1 V 107.8 V 107.5 V 107.4 V 106.5 V
Power Factor 0.717 0.718 0.723 0.727 0.730
Final Result Pass Pass Pass Pass Pass
Input Test 16 Test 17 Test 18 Test 19 Test 20 Test 21
+12VA 17 A (204 W) 18 A (216 W) 19 A (228 W) 20 A (240 W) 21 A (252 W) 22 A (264 W)
+12VB 16.5 A (198 W) 17.25 A (207 W) 18.5 A (222 W) 19 A (228 W) 20 A (240 W) 21 A (252 W)
+5V 4.5 A (22.5 W) 5 A (25 W) 5 A (25 W) 5.5 A (27.5 W) 5.5 A (27.5 W) 6 A (30 W)
+3.3 V 4.5 A (14.85 W) 5 A (16.5 W) 5 A (16.5 W) 5.5 A (18.15 W) 5.5 A (18.15 W) 6 A (19.8 W)
+5VSB 1 A (5 W) 1 A (5 W) 1 A (5 W) 1 A (5 W) 1 A (5 W) 1 A (5 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) 0.5 A (6 W)
Total 432.6 W 456.4 W 479.6 W 500.6 W 521.4 W 547.3 W
% Max Load 72.1% 76.1% 79.9% 83.4% 86.9% 91.2%
Room Temp. 45.9° C 47.7° C 49.3° C 47.1° C 49.8° C 48.3° C
PSU Temp. 42.0° C 39.8° C 40.4° C 43.3° C 44.0° C 42.7° C
Voltage Regulation Pass Pass Fail on +12VB Fail on +12VB Fail on +12 V Fail on +12 V
Ripple and Noise Pass Pass Pass Pass Pass Pass
AC Power 575.0 W 611.0 W 650.0 W 684.0 W 727.0 W 785.0 W
Efficiency 75.2% 74.7% 73.8% 73.2% 71.7% 69.7%
AC Voltage 106.7 V 106.4 V 105.0 V 106.1 V 105.0 V 103.2 V
Power Factor 0.733 0.733 0.734 0.737 0.738 0.742
Final Result Pass Pass Fail Fail Fail Fail

The Cooler Master eXtreme Power Plus 600 W, like the 550 W model from the same series, can’t deliver its labeled wattage. The power supply immediately burned when we tried to run our 600 W load pattern (which would be our test number 22). Inspecting the power supply after it burned we discovered that the component that failed was one of the switching transistors. It is also very important to note that due to the huge difference between what we were supposed to see at the +12 V output and the actual voltage being delivered by the power supply (e.g., +11.25 V during test number 21), the total wattage delivered by the power supply was way lower than it should be. For instance, the load pattern used during test 21 was supposed to extract 575 W from the power supply, but it was delivering 547.3 W during this test.

Efficiency peaked at 77.6% during test eight, with the unit delivering around 245 W, and reached its lowest point at 69.2%, with the unit delivering 84.0 W.

Voltage regulation was bad, with the power supply not being able to keep the +12 V output inside its correct value from test 18 (480 W) on. Therefore, it is only safe to pull up to 450 W from this power supply – above this value this power supply can make your computer to run unstable.

Noise and ripple levels, on the other hand, were very low at all times. During test 21 we saw a noise level of 33 mV at +12VA, 36.4 mV at +12VB, 19.2 mV at +5 V, 15.2 mV at +3.3 V, 16.6 mV at +5VSB and 35.4 mV at -12 V. As we always point out, the limits are 120 mV for +12 V and -12 V outputs, and 50 mV for +5 V and +3.3 V outputs, and all numbers are peak-to-peak figures.

[nextpage title=”Main Specifications”]

The Cooler Master eXtreme Power Plus 600 W power supply specs include:

  • ATX12V 2.3
  • Nominal labeled power: 600 W
  • Measured maximum power: 547.3 W at 48.3° C
  • Labeled efficiency: Above 70% “typically” (meaning at 50% load, or 300 W)
  • Measured efficiency: Between 69.2% and 77.6% at 115 V (nominal, see complete results for actual voltage)
  • Active PFC: No
  • 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 separate cables
  • SATA Power Connectors: Six on two cables
  • Peripheral Power Connectors: Three on one cable
  • Floppy Disk Drive Power Connectors: One
  • Protections: Over voltage (OVP), over power (OPP), and short-circuit (SCP), while under voltage protection (UVP) is present, but not listed by the manufacturer
  • Warranty: Information not available
  • Real Manufacturer: Seventeam
  • More Information: https://www.coolermaster-usa.com
  • Average price in the US*: USD 70.00

* Researched at Newegg.com on the day we published this review.

[nextpage title=”Conclusions”]

Why manufacturers like Cooler Master are still carrying power supplies with fake wattages is a mystery to us. We know that this is a very low-end power supply, but this doesn’t give the manufacturer the right to lie. This unit should be labeled as a 450 W unit and sold for half of its price. Being labeled as a 600 W product and sold for USD 70, it is a complete rip-off.

If you pull more than 450 W from this product, it will offer real risk to your computer, plus it provides poor efficiency, between 69.2% and 77.6%. If you are looking for an inexpensive yet decent power supply, get an OCZ StealthXStream 500 W. It costs less than this Cooler Master eXtreme Power Plus and presents better performance.

We also discovered that this unit is basically a Seventeam ST-500BAZ with the switching transistors upgraded, but this upgrade was too shy. The model from Seventeam uses 9 A transistors and the reviewed model uses 10 A transistors. By the way, the 550 W version of the eXtreme Power Plus and the Spire Jewel Black 650 W are simply a Seventeam ST-500BAZ power supply with a different name. In consequence, the only difference between the 550 W and the 600 W models of the eXtreme Power Plus are the switching transistors.