Cooler Master Silent Pro Gold 600W Power Supply Review

1. Introduction2. The Cooler Master Silent Pro Gold 600W PSU (External)3. The Cooler Master Silent Pro Gold 600W PSU (Internal)4. Testing Methodology and Results5. Closing Thoughts6. View All Pages

The Power Supply market is very healthy with a wealth of offerings for all user demands. Today we are focusing on the enthusiast user who wants maximum efficiency combined with the lowest possible noise for a performance gaming or media center.

The Cooler Master Silent Pro GOLD 600W power supply is built to the most demanding standards with 80 Plus GOLD certification, aimed at the high end of the market, costing £100 inc vat.

• Heat Transfer Technology
  A unique “L-shaped” heat-sink to remove heat from the PSU
• Hybrid Transformer
  Unique design that combines heat-sink with transformer
• Hyper Path
  Places IC close to transformers leading to huge efficiency ratings
• Flat modularized cables provide easy cable management leads to better airflow
• Compliance with the latest Intel standard ATX 12V V2.3
• Operation with intelligent fan speed control
• High reliability (MTBF> 100,000 hours)
• Multiple protection design (OVP/UVP/OPP/OTP/SCP/OCP)
• Japanese-made capacitors
• Five-year warranty

The Cooler Master Silent Pro 600W PSU arrives in a retina shrinking gold and black box which certainly will catch the eye in a store.

Inside, the Supply is protected by foam and is shipped inside a protective bag to stop any damage to the surface under rough shipping conditions. On top is a user manual with specifications and to the right is a box containing the accessories and cabling.

The system cabling is impressive with the ability to support both SLI and Crossfire systems with 8 pin power connectors x2 and 6 pin power connectors x 2. There is also a storage pouch supplied, always a good thing to have when you aren't using all of the cables.

There is also a CPU4/4 pin connector and 4 molex with 9 sata connectors to cover hard drives and fan demands.

The finish is beautiful – it is a Matt paintjob which does not attract finger prints or general markings. The fan, while black has a gold surround and on the sides the stickers all match the purist gold and black scheme. It is one of the most attactive power supplies we have seen at KitGuru and will look fantastic in a well built system with a side window mod.

The rear of the PSU is fully honeycomb vented to ensure maximum air flow and cooling proficency. The front supports the modular cables detailed earlier, and they are all clearly labelled and sized to ensure no one will get confused. The ports all match the muted gold colour scheme, a nice touch.

This is a single 12v rail capable of delivering 48A. The 1200W model can handle up to 98A which is a staggering output capability.

The Adda AD1212MS-A71GL is a 120mm Low Voltage Axial Fan which is an oil impregnanted sleeve bearing unit. It requires 4.08 Watt of power and operates at up to 2,050 rpm for a 80.5 CFM rated airflow capacity. The company rate the fan as producing a maximum output of 38dB, however under normal circumstances it should generate significantly less.

The internal design is very clean with massive ‘L-Shaped' heatsinks spreading across the full diameter of the PCB. These sinks are directly under the airflow of the fan and will ensure maximum cooling efficiency.

This is an Active PFC design which offers full protection for OVP/UVP/OCP/OPP/OTP and SCP. The single rail design in this particular unit delivers up to 48A on the 12V. The Hybrid Heatsink is a switching mofset design and the capacitors throughout are all Japanese made, high quality units. The VRM control transfers to 5V and 3.3V.

The design also places the IC close to the transformers which are required to create the high efficiency ratings. It complies with the latest Intel ATC 12V V2.3 standard and there is a double layer EMI filter to help reduce noise.

The cabling is fully sleeved inside the unit and is rubber protected to ensure no wires will get damaged caused by abrasion against the metal chassis.

Additional technical assistance: Peter McFarland and Jeremy Price.

Correctly testing power supplies is a complex procedure and KitGuru have configured a test bench which can deliver up to a 2,000 watt DC load. Due to public requests we have changed our temperature settings recently – previously we rated with ambient temperatures at 25C, we have increased ambient temperatures by 10c (to 35c) in our environment to greater reflect warmer internal chassis conditions.

We use combinations of the following hardware:
• SunMoon SM-268
• CSI3710A Programmable DC load (+3.3V and +5V outputs)
• CSI3711A Programmable DC load (+12V1, +12V2, +12V3, and +12V4)
• Extech Power Analyzer
• Extech MultiMaster MM570 digital multimeter
• SkyTronic DSL 2 Digital Sound Level Meter (6-130dBa)
• Digital oscilloscope (20M S/s with 12 Bit ADC)
• Variable Autotransformer, 1.4 KVA

DC Output Load Regulation
Combined DC Load	+3.3V		+5V		+12V		+5VSB		-12V
	A	V	A	V	A	V	A	V	A	V
75W	1.08	3.33	1.45	5.04	4.90	12.15	0.50	5.03	0.20	-12.09
150W	2.08	3.33	2.98	5.04	10.05	12.13	0.50	5.03	0.30	-12.09
300W	4.29	3.32	6.00	5.04	20.62	12.09	1.00	5.02	0.30	-12.11
450W	6.58	3.32	8.49	5.03	31.82	12.07	1.50	5.01	0.30	-12.11
600W	9.93	3.30	12.21	5.01	41.80	12.03	2.50	5.00	0.30	-12.12

The Cooler Master unit has good regulation across all the outputs and handles our load tests at a very capable level. All of the primary rails stayed with 2% of the nominal voltage.

Cooler Master Silent Pro Gold 600W	Maximum Load
	722.1W

We managed to get just over 720W out of the PSU before it would shut down, gracefully. We are happy to report that the overcircuit protection works well.

Next we want to try Cross Loading. This basically means loads which are not balanced. If a PC for instance needs 500W on the +12V outputs but something like 30W via the combined 3.3V and +5V outputs then the voltage regulation can fluctuate badly.

Cross Load Testing	+3.3V		+5V		+12V		-12V		+5VSB
	A	V	A	V	A	V	A	V	A	V
590W	1.0	3.33	1.0	5.05	48.0	12.01	0.2	-12.12	0.50	5.03
145W	12.0	3.31	15.0	5.03	2.0	12.08	0.2	-12.05	0.50	5.01

The Cooler Master PSU handled the Cross loading tests very well and we didn’t experience any issues at all. All the voltages remained well within specification.

We then used an oscilloscope to measure AC ripple and noise present on the DC outputs. We set the oscilloscope time base to check for AC ripple at both high and low ends of the spectrum. ATX12V V2.2 specification for DC output ripple and noise is defined in the ATX 12V power supply design guide.

ATX12V Ver 2.2 Noise/Ripple Tolerance
Output	Ripple (mV p-p)
+3.3V	50
+5V	50
+12V1	120
+12V2	120
-12V	120
+5VSB	50

Obviously when measuring AC noise and ripple on the DC outputs the cleaner (less recorded) means we have a better end result. We measured this AC signal amplitude to see how closely the Cooler Master unit complied with the ATX standard.

AC Ripple (mV p-p)
DC Load	+3.3V	+5V	+12V	5VSB
75W	15	5	20	15
150W	15	15	30	20
300W	25	25	50	25
450W	30	25	60	25
600W	35	35	85	30

Ripple results are within the parameters set down in the ATX12V Ver 2.2 standard. We recorded around 85mv of ripple on the 12V output at full load (EDIT we have updated the ripple data, the wrong data was used in this table initially – user error (yes me!)). This now falls in line with the 1200W unit from the same family we already published.

Efficiency (%)
75W	89.75
150W	90.21
300W	92.03
450W	91.67
600W	90.46

Efficiency as we hoped, is fantastic, rating over 92% at 50% load. At full load we recorded over 90% which is an exceptional result.

We take the issue of noise very seriously at KitGuru and this is why we have built a special home brew system as a reference point when we test noise levels of various components. Why do this? Well this means we can eliminate secondary noise pollution in the test room and concentrate on components we are testing. It also brings us slightly closer to industry standards, such as DIN 45635.

Today to test the Power Supply we have taken it into our acoustics room environment and have set our SkyTronic DSL 2 Digital Sound Level Meter (6-130dBa) one meter away from the unit. We have no other fans running so we can effectively measure just the noise from the unit itself.

As this can be a little confusing for people, here are various dBa ratings in with real world situations to help describe the various levels.

KitGuru noise guide
10dBA – Normal Breathing/Rustling Leaves
20-25dBA – Whisper
30dBA – High Quality Computer fan
40dBA – A Bubbling Brook, or a Refridgerator
50dBA – Normal Conversation
60dBA – Laughter
70dBA – Vacuum Cleaner or Hairdryer
80dBA – City Traffic or a Garbage Disposal
90dBA – Motorcycle or Lawnmower
100dBA – MP3 Player at maximum output
110dBA – Orchestra
120dBA – Front row rock concert/Jet Engine
130dBA – Threshold of Pain
140dBA – Military Jet takeoff/Gunshot (close range)
160dBA – Instant Perforation of eardrum

Noise (dBA)
75W	23.8
150W	25.7
300W	27.8
450W	30.2
600W	35.9

The power supply is quiet right up to 70% load when the fan starts to speed up to compensate for rising temperatures. at 450W it rates around 30 dBa rising to around 36dBa at full load. Under normal operating conditions the unit will be rating below 30 dBA which is basically silent in most living environments.

Temperature (c)
	Intake	Exhaust
75W	35	38
150W	35	38
300W	37	41
450W	41	48
600W	44	52

The Adda AD1212MS-A71GL is a great fan which can be verified above with the combination of low noise and fantastic temperatures, rising to a peak of around 8c over ambient at full load.

Maximum load	Efficiency
722.1	88.12

At 722.1W the Cooler Master Gold PSU rated just over 88% efficiency. This is not a viable ‘real world’ situation, but its interesting nonetheless.

The Cooler Master Silent Pro Gold 600W is a stellar power supply which exceeded our expectations. The 80 Plus Gold certification is well deserved as we recorded around 92% efficiency at 50% load.

While we don't often comment on the build quality, with this particular product we need to reiterate the stunning attention to detail … from the deep, high quality spray finish to the well researched cable protection system. Internally no corners have been cut with a unique L shaped heatsink design, quality Adda fan and Hybrid Transformer design which combines the heat sink with transformer.

The high efficiency and rock solid rail stability is partnered with very low noise levels, rating as silent at 50% load. Ripple is a little higher than we normally record, however it does still fall within the tolerance guidelines.

The design is minimalist, yet very attractive – reminding us a little of the recent Corsair AX products. A simple colour scheme with modern use of typography ensures that this product will attract, not offend.

If I was in the market myself for a 600W power supply and needed the highest levels of efficiency then I can rate no better. It does come with a higher price tag than most (£100 inc vat), but in this case it is worth every penny.

KitGuru says: A fantastic product with attractive design, top notch efficiency and low noise levels, making it ideal for a high quality media center or gaming system.

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