[nextpage title=”Introduction”]

When OCZ bought PC Power & Cooling, the company said that PC Power & Cooling power supplies wouldn’t have modular cabling systems. Well, scratch that. The latest release from the brand, the Silencer Mk III, features a modular cabling system and carries the 80 Plus Bronze certification, coming in 400 W, 500 W, and 600 W versions. Let’s test the 600 W version and see if it is a good choice.

The Silencer Mk III units are manufactured by Seasonic, and their internal design is different from the Silencer Mk II models.

PC Power & Cooling Silencer Mk III 600 W power supplyFigure 1: PC Power & Cooling Silencer Mk III 600 W power supply

PC Power & Cooling Silencer Mk III 600 W power supplyFigure 2: PC Power & Cooling Silencer Mk III 600 W power supply

The PC Power & Cooling Silencer Mk III 600 W is 6.3” (160 mm) deep, using a 120 mm ball bearing fan on its bottom (ADDA AD1212HB-A71GL).

As mentioned, this unit has a modular cabling system with six connectors, two for video cards or ATX12V/EPS12V power cables and four for peripheral and SATA power cables. Three cables are permanently attached to the power supply. This power supply comes with the following cables:

  • Main motherboard cable with a 20/24-pin connector, 21.6” (55 cm) long, permanently attached to the power supply
  • One cable with two ATX12V connectors that together form an EPS12V connector, 23.2” (59 cm) long, permanently attached to the power supply
  • One cable with two ATX12V connectors that together form an EPS12V connector, 23.6” (60 cm) long, modular cabling system
  • One cable with one six/eight-pin connector for video cards, 22” (56 cm) long, permanently attached to the power supply
  • One cable with one six/eight-pin connector for video cards, 22.4” (57 cm) long, modular cabling system
  • Two cables, each with three SATA power connectors, 16.5” (42 cm) to the first connector, 5.5” (14 cm) between connectors, modular cabling system
  • One cable with three standard peripheral power connectors and one floppy disk drive power connector, 22.4” (57 cm) to the first connector, 5.1” (13 cm) between connectors, modular cabling system

All wires are 18 AWG, which is the minimum recommended gauge.

The cable configuration is fair for a 600 W power supply, with two video card power connectors and six SATA power connectors.

PC Power & Cooling Silencer Mk III 600 W power supplyFigure 3: Cables

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

[nextpage title=”A Look Inside the PC Power & Cooling Silencer Mk III 600 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.

PC Power & Cooling Silencer Mk III 600 W power supplyFigure 4: Top view

PC Power & Cooling Silencer Mk III 600 W power supplyFigure 5: Front quarter view

PC Power & Cooling Silencer Mk III 600 W power supplyFigure 6: Rear quarter view

PC Power & Cooling Silencer Mk III 600 W power supplyFigure 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 this stage, the PC Power & Cooling Silencer Mk III 600 W power supply is impeccable, with four Y capacitors, one X capacitor, and one ferrite coil more than the minimum required.

PC Power & Cooling Silencer Mk III 600 W power supplyFigure 8: Transient filtering stage (part 1)

PC Power & Cooling Silencer Mk III 600 W power supplyFigure 9: Transient filtering stage (part 2)

On the next page, we will have a more detailed discussion about the components used in the PC Power & Cooling Silencer Mk III 600 W.

[nextpage title=”Primary Analysis”]

On this page we will take an in-depth look at the primary stage of the PC Power & Cooling Silencer Mk III 600 W. 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 an individual heatsink. 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.

PC Power & Cooling Silencer Mk III 600 W power supplyFigure 10: Rectifying bridge

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

PC Power & Cooling Silencer Mk III 600 W power supplyFigure 11: One of the switching transistors, the active PFC diode, and the active PFC transistors

The output of the active PFC circuit is filtered by a 560 µF x 400 V Japanese electrolytic capacitor, from Chemi-Con, labeled at 105° C.

In the switching section, another two SPP20N60C3 MOSFETs are employed using the traditional two-transistor forward configuration. The specifications for these transistors were already discussed above.

The primary is controlled by an ICE1CS02 PWM/active PFC combo controller.

PC Power & Cooling Silencer Mk III 600 W power supplyFigure 12: Active PFC/PWM controller

Let’s now take a look at the secondary of this power supply.

[nextpage title=”Secondary Analysis”]

The PC Power & Cooling Silencer Mk III 600 W 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 three SBR30A50CT Schottky rectifiers (30 A, 15 A per internal diode at 110° C, 0.55 V maximum voltage drop), which gives us a maximum theoretical current of 64 A or 771 W for this output.

The +5 V output uses one SBR40U45CT Schottky rectifier (40 A, 20 A per internal diode at 110° C, 0.52 V maximum voltage drop), which gives us a maximum theoretical current of 29 A or 143 W for this output.

The +3.3 V output uses one MBR30H30CTG Schottky rectifier (30 A, 15 A per internal diode at 138° C, 0.55 V maximum voltage drop), which gives us a maximum theoretical current of 21 A or 71 W for this output.

PC Power & Cooling Silencer Mk III 600 W power supplyFigure 13: One of the +12 V rectifiers, the +5 V rectifier, and the +3.3 V rectifier

This power supply uses an HY-510N monitoring integrated circuit, which supports only over voltage (OVP) and under voltage (UVP) protections.

PC Power & Cooling Silencer Mk III 600 W power supplyFigure 14: Monitoring circuit

The electrolytic capacitors that filter the outputs are also Japanese, from Chemi-Con and Rubycon, and are labeled at 105° C, as usual.

[nextpage title=”Power Distribution”]

Figure 15 shows the power supply label containing all the power specs.

PC Power & Cooling Silencer Mk III 600 W power supplyFigure 15: Power supply label

This power supply 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, the +12VA and +12VB inputs were connected to the power supply’s single +12 V rail.

Input Test 1 Test 2 Test 3 Test 4 Test 5
+12VA 4 A (48 W) 9 A (108 W) 13 A (156 W) 17.5 A (210 W) 21.5 A (258 W)
+12VB 4 A (48 W) 9 A (108 W) 13 A (156 W) 17.5 A (210 W) 21.5 A (258 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 A (5 W) 1.5 A (7.5 W) 2 A (10 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 114.7 W 241.8 W 354.4 W 478.4 W 597.4 W
% Max Load 19.1% 40.3% 59.1% 79.7% 99.6%
Room Temp. 46.4° C 45.0° C 45.6° C 47.0° C 44.9° C
PSU Temp. 48.2° C 47.7° C 47.8° C 48.7° C 50.2° C
Voltage Regulation Pass Pass Pass Pass Pass
Ripple and Noise Pass Pass Pass Pass Pass
AC Power 134.5 W 280.2 W 416.7 W 574.1 W 734.0 W
Efficiency 85.3% 86.3% 85.0% 83.3% 81.4%
AC Voltage 117.1 V 115.7 V 114.4 V 112.9 V 111.2 V
Power Factor

0.995

0.996

0.997

0.997

0.996

Final Result Pass Pass Pass Pass Pass

The PC Power & Cooling Silencer Mk III 600 W can really deliver its labeled wattage at high temperatures.

Efficiency was between 83.3% and 86.3% when we pulled between 20% and 80% of the unit’s labeled wattage (i.e., between 120 W and 480 W), but at full load, efficiency dropped a little bit below the 82% mark promised by the 80 Plus Bronze certification, at 81.4 percent. This happens because the 80 Plus tests are conducted at 23° C. We test power supplies at a temperature of at least 45° C, and efficiency drops with temperature.

Voltage regulation was excellent, with all positive voltages closer to their nominal values than necessary (three percent regulation). The -12 V output was outside this tighter range during test one, but still inside the allowed margin. All voltages were still inside the proper range. 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 PC Power & Cooling Silencer Mk III 600 W provided extremely low ripple and noise levels during all tests, as you can see in the table below.

Input Test 1 Test 2 Test 3 Test 4 Test 5
+12VA 13.4 mV 13.2 mV 14.4 mV 16.2 mV 19.8 mV
+12VB 13.8 mV 14.6 mV 15.2 mV 17.0 mV 22.4 mV
+5 V 10.2 mV 9.2 mV 9.4 mV 10.0 mV 9.6 mV
+3.3 V 8.2 mV 8.6 mV 9.0 mV 10.0 mV 16.4 mV
+5VSB 12.2 mV 12.4 mV 15.2 mV 16.8 mV 20.2 mV
-12 V 9.6 mV 9.0 mV 10.4 mV 12.4 mV 14.8 mV

Below you can see the waveforms of the outputs during test five.

PC Power & Cooling Silencer Mk III 600 W power supplyFigure 16: +12VA input from load tester during test five at 597.4 W (19.8 mV)

PC Power & Cooling Silencer Mk III 600 W power supplyFigure 17: +12VB input from load tester during test five at 597.4 W (22.4 mV)

PC Power & Cooling Silencer Mk III 600 W power supplyFigure 18: +5V rail during test five at 597.4 W (9.6 mV)

PC Power & Cooling Silencer Mk III 600 W power supplyFigure 19: +3.3 V rail during test five at 597.4 W (16.4 mV)

Let’s see if we can pull more than 600 W from this unit.

[nextpage title=”Overload Tests”]

Below you can see the maximum we could pull from this power supply. If we tried to pull more than what is described in the table below, the total wattage would decrease instead of increase, showing us that the power supply had already reached its limit. During this test, all voltages were still within 3% of their nominal values, and ripple and noise levels were still extremely low.

Input Overload Test
+12VA 26 A (312 W)
+12VB 26 A (312 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 712.1 W
% Max Load 118.7%
Room Temp. 43.0° C
PSU Temp. 52.1° C
AC Power 907 W
Efficiency 78.5%
AC Voltage 109.4 V
Power Factor 0.996

[nextpage title=”Main Specifications”]

The main specifications for the PC Power & Cooling Silencer Mk III 600 W power supply include:

  • Standards: NA
  • Nominal labeled power: 600 W at 50° C
  • Measured maximum power: 712.1 W at 43° C
  • Labeled efficiency: 85% at typical load (i.e., 50% load or 300 W), 80 Plus Bronze certification
  • Measured efficiency: Between 81.4% and 86.3%, at 115 V (nominal, see complete results for actual voltage)
  • Active PFC: Yes
  • Modular Cabling System: Yes
  • Motherboard Power Connectors: One 20/24-pin connector and two ATX12V connectors that together form an EPS12V connector permanently attached to the power supply, and two ATX12V connectors that together form an EPS12V connector on the modular cabling system
  • Video Card Power Connectors: Two six/eight-pin connectors, one permanently attached to the power supply and one on the modular cabling system
  • SATA Power Connectors: Six on two cables, modular cabling system
  • Peripheral Power Connectors: Three on one cable, modular cabling system
  • Floppy Disk Drive Power Connectors: One
  • Protections (as listed by the manufacturer): Over voltage (OVP) and over power (OPP) protections
  • Are the above protections really available? Yes. This unit also has under voltage (UVP) and short-circuit (SCP) protections.
  • Warranty: Five years
  • Real Manufacturer: Seasonic
  • More Information: http://www.pcpower.com
  • Average Price in the US*: USD 90.00

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

[nextpage title=”Conclusions”]

The new PC Power & Cooling Silencer Mk III 600 W is a very good unit, with efficiency between 81.4% and 86.3%, voltages closer to their nominal values than necessary (three percent voltage regulation), and extremely low noise and ripple levels. The cable configuration is fair for a 600 W unit.

This unit is being sold for USD 90, but if you live in the United States, you can get a USD 20 mail-in rebate, making its final price USD 70, which is an outstanding price for this power supply. The problem is that most users forget to send in the documentation to get the rebate, plus the time it takes (sometimes months) to get the rebate card back.

Also, at USD 90 it is still cheaper than its main competitors, which include the Corsair TX550M at USD 100 and the OCZ ZT Series 550 W, also at USD 100. It costs the same as the OCZ ZS Series 650 W, which doesn’t come with a modular cabling system but gives you an extra 50 W of power. And, if you are looking for a cheaper option in this power range, the Enermax NAXN 82+ 550 W at USD 75 is also a good option, although it doesn’t come with a modular cabling system.