be quiet! Straight Power 11 Platinum 850W Review

1. Introduction2. Bundle & Cabling3. External4. Internal5. Testing Methodology and Results6. Closing Thoughts7. View All Pages

Today we take a look a power supply from be quiet! – from their new Straight Power 11 range. They claim this is their quietest power supply range yet and we have the 850W model up for test today. These new power supplies are now Platinum certified and have received some other tweaks to modernise them for 2020.

The main talking point will obviously be the move from Gold efficiency rating to Platinum efficiency. be quiet! say they have optimised the layout, moved from a half bridge to full bridge topology and replaced some of the internal components. This Full Bridge + LLC + SR + DC-to-DC topology helps achieve the highest possible efficiency. This new range of power supplies are equipped with up to six daughter cards providing Full Bridge conversion, DC to DC transformation, LLC and Synchronous rectification.

The new range of Straight Power 11 are available at up to 1200 watts, giving a 200 watt boost over the previous Gold efficiency generation. The 650W model in the range now ships with a second P8 connector which will help deliver higher levels of power to more demanding processors on the market today. Surprisingly, there is only a 5 year warranty with these models which seems rather short compared to brands such as Seasonic (who offer 12 year warranty on their Platinum models).

FEATURES

• 80 PLUS® Platinum certification with an outstanding efficiency of up to 93,8%
• Virtually inaudible operation thanks to a Silent Wings 3 135mm fan
• Big funnel-shaped fan opening of the PSU case for high airflow intake
• Wire-free on the DC side inside the PSU for enhanced cooling and longevity
• Modular cables for maximum build flexibility
• Advanced stability and voltage regulation thanks to LLC, SR and DC-to-DC
• Four high-performance 12V rails
• Powerful multi-GPU support with two PCI-Express connectors
• Japanese 105°C-rated capacitors ensure stability and reliability
• Power signal stability unmatched in its class
• ErP and Energy Star 7.0 ready
• 5-year manufacturer’s warranty
• Product conception, design and quality control in Germany

be quiet! artwork has not changed in many years – and we see no reason it would – the black and orange accented art style is very effective. The front of the box showcases a high resolution image of the power supply along with some key details such as efficiency, the proprietary ‘Silent Wings' Fans and ‘Full Cable Management' features.

The rear of the box highlights some of the new design implementation including the ‘wire free on the DC side' part of the structure.

The power supply is a pure modular design meaning that you only need to connect the cables you actually need.

The be quiet! power supply is finished to a high standard – very understated in appearance.

The large fan is hidden behind the metal grille – we will take a look at the fan later when we open the unit.

One side of the power supply is vented to allow for air flow. There is a power switch and connector at the side.

The other side of the power supply is home to the modular bay for the connectors – all in vertical rows and clearly labelled.

be quiet! Straight Power 11 Platinum 850W
DC Output	+3.3V	+5V	+12V1/2/3/4	-12V	+5Vsb
Max Output	25A	25A	21A/21A/26A/26A	0.5A	3A
Total Power	150W		70.8A/849.6W	6W	15W
	850W

this be quiet! unit has four 12V rails. V1 and V2 both put out 21A, and V3 and V4 deliver 26A each. The maximum output is 70.8A. The core audience like to see single rail power supplies – but in reality, if it is a good design it won't really make much difference in the real world.

be quiet! silent wings fans are superb. This particular power supply is using model number BQ SIW3-13525-HF, rated at 0.56A, 12V and rated at 2,100 rpm.

This looks to be an FSP partner design, but I am not completely positive about that. The design is quite clean with good soldering throughout. There are high grade Japanese 105c rated Nippon Chemi Con capacitors (KMR series) in the primary stage. 2x 420V 330uF for a total of 660uF. To achieve Platinum efficiency with the new design some internal changes have taken place.

 

The higher watt models (from 850W up) use two transformers now instead of a single larger transformer. This helps reduce temperatures, and increases efficiency. It also helps reduce overall component height inside the unit, enhancing air circulation.

The Straight Power 11 LLC design uses both pulse width modulation (PWM) and frequency modulation (FM)  to adjust power transformation. When loads hit 10 to 15 percent the LLC circuit modifies the frequency to improve the results. The LLC circuit is controlled by the CM6901 integrated circuit.

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. We run at 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

We test in a single +12V configuration.

DC Output Load Regulation
Combined DC Load	+3.3V		+5V		+12V		+5VSB		-12V
	A	V	A	V	A	V	A	V	A	V
85W	0.95	3.34	0.92	5.01	6.00	12.02	0.50	5.02	0.20	-12.03
170W	1.70	3.34	1.67	5.00	12.35	12.01	1.00	5.01	0.20	-12.03
425W	3.00	3.33	3.05	5.00	32.20	12.00	1.50	5.01	0.30	-12.01
640W	4.05	3.32	4.05	5.00	49.00	11.97	2.00	5.01	0.30	-12.01
850W	5.00	3.32	5.23	5.00	65.52	11.95	2.50	5.01	0.50	-12.01

Load regulation is very strong with the rails holding with 1.5% of recommended specifications.

be quiet! Straight Power 11 Platinum 850W	Maximum Load
	943W

We managed to get the power supply to deliver 943W before it would shut down, delivering around 93W more than 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	3.33	1.0	5.01	60.0	11.95	0.2	-12.02	0.50	5.01
165W	15.0	3.32	18.0	4.97	2.0	12.02	0.2	-12.01	0.50	5.02

The power supply dealt with the demanding cross load test very well exhibiting little fluctuation. It was tasked with 60A on the +12V rail and it held at 11.95V. The other rails delivered solid results also.

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	10	5
225W	5	10	10	5
450W	10	10	15	5
675W	15	15	20	10
850W	15	15	25	15

Noise suppression is very good indeed with both the primary and minor rails exhibiting great all round results and well within industry rated parameters.

Efficiency (%) 240V
100W	90.7
225W	92.3
450W	94.1
675W	93.2
850W	91.4

As we would expect efficiency levels are very high across the range of loads – peaking at just over 94% around 55% load. This hits Platinum efficiency as the company claim.

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 Refrigerator
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	<28.0
225W	29.4
450W	33.3
675W	35.8
850W	36.3

We really do rate the be quiet! Silent Wings fans very highly and this shows that throughout the load range the fan noise emissions are well under control – even at full load we wouldn't call the fan too intrusive. The pitch is quite low, so it is not that noticeable, especially when you would have other fans running in a system build.

Temperature (c)
	Intake	Exhaust
100W	37	39
225W	38	43
450W	39	45
675W	43	51
850W	45	54

The large fan spins quite slowly at lower load levels due to the efficiency of the unit. Temperatures are well maintained throughout the full range of loads.

Maximum load	Efficiency
933 watts	90.5

At 943 watts, this unit managed to deliver efficiency at 90.5%.

The Straight Power range of power supplies has been popular for be quiet! over the years. The latest Straight Power 11 supplies are without question be quiet!'s finest yet. The new range with higher wattage models is a good move and the upgrade to 80 Plus Platinum is surely a way to appeal to the demanding enthusiast audience in 2020.

Technically the new design is very capable. The unit we tested achieved 80 Plus Platinum efficiency levels, peaking at just over 94% around 50% load. The many refinements to the design have modernised the platform, making it perform at a higher level all round.

The unit incorporates a quality SilentWings fan and as the name suggests it is very quiet at high load and in real world terms it is unlikely you will ever hear it in operation, especially with other fans inside a chassis.

The Straight Power 11 Platinum ticks the boxes – it is a fully modular design, technically very capable and is aggressively priced in the United Kingdom. I am a little surprised that be quiet! only offer a 5 year warranty, however this might not be that much of a problem for a percentage of the audience interested in a new supply.

You can buy the be quiet! Straight Power 11 Platinum 850W from Overclockers UK for £149.99 inc vat HERE.

Discuss on our Facebook page HERE.

Pros:

• Competitively Priced.
• Well built unit.
• Good design.
• Technically very solid.
• Japanese capacitors throughout.
• was able to maintain over 930 watts without shutting down.

Cons:

• 5 year warranty could be better in 2020.

Kitguru says: the be quiet! Straight Power 11 Platinum 850W is a very capable power supply competitively priced in the UK. It definitely should be shortlisted if you are in the market for a high capacity unit for a new system build.

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