Cooler Master Silent Pro Hybrid 850W Power Supply Review

1. Introduction2. Cooler Master Silent Pro Hybrid 850W (Bundle & Cables)3. Cooler Master Silent Pro Hybrid 850W (External)4. Cooler Master Silent Pro Hybrid 850W (Internal)5. Cooler Master Silent Pro Hybrid 850W (Super High Res Gallery)6. Testing Methodology & Results7. Closing Thoughts8. View All Pages

Today we are looking at a power supply from Cooler Master called the ‘Silent Pro Hybrid'. This is based around the Silent Pro Gold Model, but it features a high grade cooling fan with hydraulic bearings … this stops rotating completely when the loads are below 200W. Cooler Master have a 1300W, a 1050W and an 850W in the range and we are looking at the smallest, most affordable supply in the series.

The Cooler Master Silent Pro Hybrid 850W power supply is a fully modular design which is 80 Plus Gold Certified and uses high grade Japanese capacitors for long life. It is also ErP Lot6 compliant, meaning a very low wattage power drain when powered off (less than 1W).

Cooler Master also bundle a dedicated 5.25 inch fan speed controller in the package which can control the power supply fan and three additional system fans.

Main Features:

• Fully modular cables
• Noise-free Operation
• World’s first PSU integrated 7V fan port
• Auto Fanless mode under 200W loading
• 5.25” drive bay fan controller for both the PSU and three system fans
• Speed adjustable 135mm Super Silent Hydraulic Bearings Fan
• Over 90% efficiency with 80Plus Gold Certification

The Cooler Master Silent Pro Hybrid 850W ships in a beautiful purple and white box with a high resolution image of the product in the middle. The 80 Plus Gold Certification logo is highlighted on the front of the box, along with the 5 year warranty.

The box opens along the length, and there are two separate sections for the cables and accessories. The power supply itself is underneath a user manual and warranty card.

The bundle includes a fan controller, a manual, warranty card, fixing screws for power supply and fan controller and a pouch of modular cables.

The fan controller is a worthy addition to the bundle and will be useful for many people who buy the power supply. This is installed into a free 5.25 inch drive bay and is connected to the power supply with a four pin wire, which also feeds enough power for operation.

There are two controller pads to offer fan adjustment and the main switch can be toggled to manual mode to control three more fans inside the main computer chassis. You can even lower the speed of the fan inside the power supply, but we suggest you are careful because if you set it to the lowest speed it could trip the OVP (Over Temperature Protection).

Cooler Master supply a great looking bag to store the excess cables. As the Silent Pro Hybrid is a pure modular design this comes in very handy. Many of the cables are ‘flat' which is ideal for routing in a space restricted chassis.

They supply the following cables:

• 1 x M / B 24 pins (650mm)
• 2x CPU 4 + 4 pins (700mm)
• 6x PCI-e 6+2 pins (600mm)
• 2x SATA (500mm + 100mm)
• 5x Peripheral 4 pins (500mm + 100mm)
• x1 Floppy 4 pins
• x3 Fan cable 3 pins (460mm)

The Cooler Master Silent Pro Hybrid 850W is an attractively finished power supply, with a smooth clean paint finish on all corners. It is a simple, subtle design finished in plain dark colours with the model name on the sides in bright lettering.

The power supply measures 150mm x 180 mm x 86 mm. We wouldn't say the surface was quite as resilient to damage as the Enermax Platimax power supplies which we have reviewed recently, but it is quite difficult to scratch.

The large 135mm fan is a ‘Silent Hydraulic Bearing' design which is rated to generate very low levels of noise in the automatic profile setting. We like the appearance of the accented grey inner shield area, surrounding the fan. Cooler Master have placed a logo right in the center of the fan area.

The rear of the power supply has honeycomb vents for maximum airflow. At the left is a power connector and switch.

The modular panel is cleanly arranged, colour coded and labeled. This ensures that the installation phase is straightforward, even for an inexperienced system builder.

Cooler Master 850W Silent Pro Hybrid Power Supply
DC Output	+3.3V	+5V	+12V	-12V	+5Vsb	+7V
Max Output	22A	25A	70A	0.3A	3A	1.8A
Total Power	150W		840W	3.6W	15W	12.6W
	850W

Cooler Master have included a dedicated +7V rail which can offer up to 1.8A to handle two external fans. We think this is the first time this has even been included within a power supply. The +12V rail can handle up to 70A, which is going to accommodate a high powered gaming system with multiple graphics cards.

The Cooler Master fan is actually made by Young Lin Tech Co Ltd. We have seen this fan used in other Cooler Master power supplies, although this time Cooler Master have ‘branded' it with their own sticker. The fan is rated to 2,000 rpm, with an airflow of 82.41 CFM generating a maximum noise level of 37.98 dBa.

Cooler Master have partnered with Enhance for this specific design. They are using several rows of large heatsinks to cover the full length of the PCB. We would assume they are playing it safe by using large heatsinks to help ensure that the large fan can spin as slowly as possible, especially if a user lowers the fan rotation speed with manual settings.

The Silent Pro Hybrid 850W uses a single X and two Y Caps on the AC receptacle. There are two pairs of Y and X caps, an MOV, two CM chokes and a thermistor on the main PCB.

The design uses two primary capacitors rated 330 uF, 420V @ 105c.

The main transformer is a hybrid design combining the transformer and heatsink into a single entity. This should mean higher efficiency due to reduced temperatures and transformer size.

On this page we present some super high resolution images of the product taken with the 24.5MP Nikon D3X camera and 24-70mm ED lens. These will take much longer to open due to the dimensions, especially on slower connections. If you use these pictures on another site or publication, please credit Kitguru.net as the owner/source.

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
• Extech digital sound level meter
• Digital oscilloscope (20M S/s with 12 Bit ADC)
• Variable Autotransformer, 1.4 KVA

12V output is combined for our testing.

DC Output Load Regulation
Combined DC Load	+3.3V		+5V		+12V		+5VSB		-12V
	A	V	A	V	A	V	A	V	A	V
100W	1.50	3.37	1.77	5.09	6.65	12.21	0.50	5.09	0.20	-12.19
225W	3.76	3.35	3.80	5.05	15.55	12.18	1.00	5.05	0.20	-12.17
450W	7.50	3.33	8.33	5.02	30.79	12.11	1.50	5.02	0.30	-12.12
675W	11.30	3.32	12.31	4.96	47.52	12.05	2.00	5.00	0.50	-12.09
850W	1.47	3.28	1.15	4.88	63.49	12.01	0.50	4.95	0.20	-12.03

The supply produces decent load regulation across the +12V output. The +5V output drops to 4.88 at full load however, which is not ideal.

Cooler Master Silent Pro Hybrid 850W	Maximum Load
	911W

We managed to get the PSU to achieve 912W before it would shut down, delivering around 61W more than the rated specifications.

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
760W	1.0	3.37	1.0	5.09	60.0	11.99	0.2	-12.06	0.50	5.05
165W	15.0	3.27	18.0	4.86	2.0	12.18	0.2	-12.03	0.50	5.03

The power supply passed the cross load tests, although their was a noticeable variable from the +5V output, dropping 0.23 when loaded with 18A.

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 unit complied with the ATX standard.

AC Ripple (mV p-p)
DC Load	+3.3V	+5V	+12V	5VSB
100W	5	5	15	5
225W	10	10	20	10
450W	10	10	30	10
675W	10	10	35	10
850W	15	15	45	15

Ripple results are extremely impressive across all output with the +3.3V and +5V output peaking at only 15 mV. The +12 output peaks at 45 mV at 100% load. These results are very good.

Efficiency (%)
100W	87.33
225W	89.21
450W	91.77
675W	90.45
850W	89.10

The efficiency of the power supply is very good, hitting almost 92 percent at 50 percent load, dropping back to 89 percent at full load.

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 Digital Sound Level Noise Decibel Meter Style 2 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)
100W	29.0
225W	31.4
450W	32.1
675W	34.2
850W	35.3

The power supply is silent at 100W-150W, and when the fan kicks in this rises to an average emission around 32 dBa under general use. This translates to a power supply which is inaudible between 10% and 60% load. When loaded with 650W+ the fan spins up to compensate for rising temperatures. The noise levels peak at 35.3 dBa at full load which is clearly audible.

That said, the user could balance the noise levels manually via the supplied controller, but we really don't recommend anything but a very minor ‘tweak' to slightly lower fan noise if you are loading the power supply at 600W or more when gaming.

Temperature (c)
	Intake	Exhaust
100W	35	39
225W	37	43
450W	42	49
675W	43	53
850W	47	57

The large fan performs reasonably well, peaking at a maximum 10c above ambient threshold at full load.

Maximum load	Efficiency
911W	87.5%

At 911w, the efficiency level is still strong, measuring 87.5%. Not a practical situation to be running 24/7, but worth noting.

There is no doubt that the Cooler Master Silent Pro Hybrid 850W is a capable, well designed power supply, both in regards to the build quality and overall technical performance.

First impressions are positive, in part thanks to the generous bundle, including a useful 5.25 inch three fan controller. The pure modular design deserves special mention due to the clear labeling, port colouring and high grade cabling supplied in the box. The quality of the chassis, including the paintwork is first class.

That said, we do still feel the high end Enermax Platimax units have a better ‘textured' finish to resist against scratching and fingerprints however.

Technically, the power supply has been carefully designed to manage noise suppression exceptionally well and it passes this particular test with flying colours. The quality fan selection ensures modest noise emissions, with the Silent Pro Hybrid 850W remaining inaudible until the last 200W of total power output.

This power supply would be ideal in a high powered media center, as the fan would be inactive when gently loaded, for instance when watching a Bluray movie. When gaming, the fan would kick in to ensure stability under load. Corsair used a similar system in the past with their high end power supplies, and it works well.

We do have a few minor concerns. Firstly, the load regulation could have been handled better by Enhance. We recorded a marginal drop on the +5V output and this was also highlighted with the cross loading test. It didn't cause any real world issues, but it gave us enough concern to highlight it.

The inclusion of a 7V rail is creative, and we like the idea of controlling several case fans via the dedicated fan controller. Our only concern is that the Silent Pro Hybrid 850W fan speed could be reduced too much, causing potential long term reliability concerns. We really do recommend that the internal fan is left on the ‘automatic' setting as it is well balanced in regards to temperature and airflow noise.

This is a rather difficult power supply to source in the United Kingdom, but we found it in the UK via Amazon partners. They are stocking it for £185 inc vat, which raised an eyebrow.

For £20 more you can get the Enermax Platimax 850W power supply which is technically a superior design. It offers improved efficiency (80 Plus Platinum rated) and has rock solid load regulation. Granted you don't get a pure modular design or a fan controller, but I much prefer the Enermax product.

If you can find the Cooler Master Silent Pro Hybrid 850W for around £160 it becomes a much more tempting proposition.

Pros:

• Great appearance.
• quiet under general load situations.
• pure modular design.
• good quality build.
• great efficiency.

Cons:

• Load regulation could be better.
• very expensive.

Kitguru says: A very capable power supply, but it is expensive and faces very stiff competition at this price, especially if you have no interest in the fan controller.

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