[nextpage title=”Introduction”]

The Silencer Mk II power supply series from PC Power & Cooling is comprise with 500 W, 650 W, 750 W and 950 W models. The 650 W, 750 W and 950 W models come with 80 Plus Silver certification, synchronous design with DC-DC conversion, and seven-year warranty, but the entry-level 500 W model comes with 80 Plus Bronze certification, traditional design, and five-year warranty. Therefore, the 500 W model doesn’t share the same internal platform as the other models. We’ve already tested the 650 W and 750 W versions, and both proved to be excellent products. Let’s see if the 500 W model is also a good option.

The power supplies from Silencer Mk II series are manufactured by Highpower.

Figure 1: PC Power & Cooling Silencer Mk II 500 W power supply

Figure 2: PC Power & Cooling Silencer Mk II 500 W power supply

The PC Power & Cooling Silencer Mk II 500 W is 6.3” (160 mm) deep, using a 135 mm fan on its bottom. This fan is a Globe Fan RL4Z-B1352512H, which is a ball-bearing fan with a maximum rotation of 1,500 rpm and a maximum airflow of 106.86 cfm.

This unit features active PFC, of course, and following PC Power & Cooling tradition, it doesn’t come with a modular cabling system. The cables included are the following:

• Main motherboard cable with a 20/24-pin connector, 19.3” (49 cm) long
• One cable with one ATX12V connector, 22.4” (57 cm) long
• One cable with one EPS12V connector, 22.4” (57 cm) long
• One cable with one six/eight-pin connector for video cards, 22.4” (57 cm) long
• One cable with one six-pin connector for video cards, 22.4” (57 cm) long
• Two cables, each with four SATA power connectors, 22.4” (57 cm) to the first connector, 5.5” (14 cm) between connectors
• One cable with four standard peripheral power connectors, 23.6” (60 cm) to the first connector, 5.5” (14 cm) between connectors
• One cable with three standard peripheral power connectors and one floppy disk drive power connector, 23.6” (60 cm) to the first connector, 5.9” (15 cm) between connectors

All wires are 18 AWG, except the orange (+3.3 V) wires in the main motherboard cable, which are thicker (16 AWG).

The cable configuration is outstanding for a 500 W product. In fact, this practically the same configuration used on the 650 W model, the only difference between the two is that the 500 W model comes with one additional peripheral power connector, whereas the 650 W model has one additional floppy disk drive power connector.

Figure 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 II 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. The printed circuit board of the Mk II 500 W is completely different from the one used on the 650 W and 750 W models. So while the 650 W and 750 W models share the same design, the 500 W model is based on a different one.

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 this power supply, this stage is flawless. It has 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)

In the next page we will have a more detailed discussion about the components used in the PC Power & Cooling Silencer Mk II 500 W.

[nextpage title=”Primary Analysis”]

On this page we will take an in-depth look at the pr
imary stage of the PC Power & Cooling Silencer Mk II 500 W. For a better understanding, please read our Anatomy of Switching Power Supplies tutorial.

This power supply uses one GBU805 rectifying bridge on its primary attached to the same heatsink as the active PFC transistors. This component supports up to 8 A at 100° C, so in theory, you would be able to pull up to 920 W from a 115 V power grid. Assuming 80% efficiency, the bridge would allow this unit to deliver up to 736 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.

Figure 10: Rectifying bridge

The active PFC circuit uses two FMV19N60E MOSFETs, each one capable of delivering up to 19 A at 25° C (unfortunately the manufacturer doesn’t say the limit at 100° C) in continuous mode, or up to 76 A in pulse mode at 25° C. These transistors present a 310 mΩ 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 have a higher efficiency.

Figure 11: Active PFC transistors

The electrolytic capacitor that filters the output of the active PFC circuit is Japanese, from Chemi-Con, and labeled at 105° C.

In the switching section, another two FMV19N60E MOSFETs power MOSFETs are used in the traditional two-transistor forward configuration.

Figure 12: Switching transistors

The primary is controlled by a FAN4800 active PFC/PWM combo.

Figure 13: Active PFC/PWM combo controller

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

[nextpage title=”Secondary Analysis”]

As explained in the Introduction, the 500 W model uses a different design on the secondary compared to the more powerful members in the Silencer Mk II family: it uses a traditional design using Schottky rectifiers, while the other models use a synchronous design (meaning that the Schottky rectifiers were replaced by MOSFET transistors in order to increase efficiency) with DC-DC converters (the +5 V and +3.3 V outputs are generated by two small power supplies attached to the +12 V output).

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%.

The +12 V output uses two S30D60C Schottky rectifiers, each one supporting up to 30 A (15 A per internal diode at 125° C, 0.70 V maximum voltage drop), giving us a maximum theoretical current of 43 A or 514 W for the +12 V output.

The +5 V output uses two S30D45C Schottky rectifiers, giving us a maximum theoretical current of 43 A or 214 W for the +5 V output.

The +3.3 V output uses another two S30D45C Schottky rectifiers, giving us a maximum theoretical current of 43 A or 141 W for the +3.3 V output.

All these numbers are theoretical. The real amount of current/power each output can deliver is limited by other components, especially by the coils used on each output.

Figure 14: +5VSB, +3.3 V, +5 V and +12 V rectifiers

This power supply uses a PS224 monitoring integrated circuit, which supports over voltage (OVP), under voltage (UVP) and over current (OCP) protections. The over current protection circuit available in this integrated circuit has four channels, one for +3.3 V, one for +5 V, and two for +12 V. However, in this power supply only one +12 V OCP channel is used, as it has a single-rail design.

Figure 15: Monitoring circuit

The electrolytic capacitors available in the secondary are from also Japanese, from Chemi-Con, and labeled at 105° C.

[nextpage title=”Power Distribution”]

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

Figure 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 500 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 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 were connected to the power supply single +12 V rail (the EPS12V connector was installed on the +12VB input).

Input	Test 1	Test 2	Test 3	Test 4	Test 5
+12VA	4 A (48 W)	7.5 A (90 W)	11 A (132 W)	14 A (168 W)	17.5 A (210 W)
+12VB	3 A (36 W)	7 A (84 W)	10.5 A (126 W)	14 A (168 W)	17.5 A (210 W)
+5V	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)	2.5 A (12.5 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	104.2 W	203.0 W	306.2 W	402.6 W	502.4 W
% Max Load	20.8%	40.6%	61.2%	80.5%	100.5%
Room Temp.	45.6° C	44.8° C	44.2° C	44.9° C	46.0° C
PSU Temp.	49.5° C	49.3° C	49.2° C	49.6° C	50.8° C
Voltage Stability	Pass	Pass	Pass	Pass	Pass
Ripple and Noise	Pass	Pass	Pass	Pass	Pass
AC Power	123.2 W	236.2 W	360.0 W	481.8 W	617.2 W
Efficiency	84.6%	85.9%	85.1%	83.6%	81.4%
AC Voltage	117.8 V	117.1 V	115.1 V	114.4 V	113.6 V
Power Factor	0.975	0.960	0.980	0.987	0.990
Final Result	Pass	Pass	Pass	Pass	Pass

The PC Power & Cooling Silencer Mk II 500 W can really deliver its labeled wattage at high temperatures.

Efficiency was high, between 81.4% and 85.9%. Efficiency at full load was a little bit below what is required by the 80 Plus Bronze certification (82%), but as we always explain, tests performed by 80 Plus are done at a room temperature of only 23° C, while this particular power supply we tested around 45° C, and efficiency drops with temperature.

Voltage regulation was superb, with all voltages within 3% of their nominal values, including the -12 V output. This means that voltages were closer to their nominal values than required by the ATX12V specification, which says positive voltages must be within 5% of their nominal values and negative voltages must be within 10% of their nominal values.

Noise and ripple levels were always below the maximum allowed. 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.

Figure 17: +12VA input from load tester during test five at 502.4 W (62.2 mV)

Figure 18: +12VB input from load tester during test five at 502.4 W (59.8 mV)

Figure 19: +5V rail during test five at 502.4 W (34.8 mV)

Figure 20: +3.3 V rail during test five at 502.4 W (23.8 mV)

Let’s see if we can pull even more from the PC Power & Cooling Silencer Mk II 500 W.

[nextpage title=”Overload Tests”]

Below you can see the maximum we could pull from this power supply. If we tried to increase one amp at any given output, the unit would shut down, showing that one of its protections kicked in, which is always the desired behavior. During this test, the noise level at -12 V output was at 146.6 mV, surpassing the maximum allowed (120 mV). All voltages were still within 3% of their nominal values. It is interesting to note that the manufacturer labels this unit as having 600 W peak power.

Input	Overload Test
+12VA	24 A (288 W)
+12VB	24 A (288 W)
+5V	10 A (50 W)
+3.3 V	10 A (33 W)
+5VSB	2.5 A (12.5 W)
-12 V	0.5 A (6 W)
Total	670.2 W
% Max Load	134.0%
Room Temp.	48.5° C
PSU Temp.	54.4° C
AC Power	866 W
Efficiency	77.4%
AC Voltage	110.7 V
Power Factor	0.994

[nextpage title=”Main Specifications”]

The specs of the PC Power & Cooling Silencer Mk II 500 W include:

• Nominal labeled power: 500 W continuous at 45° C, 600 W peak
• Measured maximum power: 670.2 W at 48.5° C ambient
• Labeled efficiency: 85% at typical load (i.e., 50% load or 250 W), 80 Plus Bronze certification
• Measured efficiency: Between 81.4% and 85.9% 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, one ATX12 V connector, and one EPS12V connector
• Video Card Power Connectors: one six-pin and one six/eight-pin on separate cables
• SATA Power Connectors: Eight on two cables
• Peripheral Power Connectors: Seven on two cables
• Floppy Disk Drive Power Connectors: One
• Protections (as listed by the manufacturer): Over voltage (OVP), over current (OCP) and over temperature (OTP)
• Are the above protections really available? Yes, and although not listed by the manufacturer, this unit also has under voltage (UVP) and short-circuit (SCP) protections
• Warranty: Five years
• Real Manufacturer: Highpower
• More Information: https://www.pcpower.com
• Average price in the US*: Between USD 72.00 and USD 95.00

* Researched at Google Shopping on the day we published this review.

[nextpage title=”Conclusions”]

The PC Power & Cooling Silencer Mk II 500 W is a good power supply, with high efficiency (between 81.4% and 85.9%), superb voltage regulation, low noise and ripple levels, and a very good cable configuration for a 500 W model (the same configuration used on the 650 W model from the same series).

It is very important to understand that the 500 W model uses a completely different internal design compared to the more powerful models from the Silencer Mk II series.

This is one of the best 500 W power supplies we’ve reviewed to date, however you can buy the OCZ ModXStream Pro 500 W, which has similar performance and comes with a modular cabling system, for less. Because it is a little bit expensive, in our opinion, we are giving the PC Power & Cooling Silencer Mk II 500 W with our Silver Award.

The only 500 W power supply we reviewed that is better than the Silencer Mk II and the OCZ ModXStream Pro is the Enermax PRO87+ 500 W, which is an 80 Plus Gold unit and costs far more.