Be Quiet! 850W Straight Power 11 PSU, Fully Modular, 80+ Platinum
Review: 5 - "A masterpiece of literature" by , written on May 4, 20020
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Be Quiet! 850W Straight Power 11 PSU, Fully Modular, 80+ Platinum


be quiet! Straight Power 11 Platinum 850W raises the bar for systems that demand virtually inaudible operation and outstanding efficiency.

  • 80 PLUS® Platinum efficiency (up to 94%)

  • Virtually inaudible Silent Wings 3 135mm fan

  • Funnel-shaped fan opening of the PSU case for high airflow intake

  • Wire-free inside the PSU on the DC side for enhanced cooling and longevity 

  • Modular cables for maximum build flexibility

  • Powerful multi-GPU support with four PCI-Express connectors

  • Japanese 105°C-rated capacitors ensure stability and reliability

  • ErP and Energy Star 7.0 ready

  • 5-year manufacturer’s warranty

80 Plus Platinum Certified

One of the highest efficiency certificates available

Straight Power 11 Platinum 850W is certified with 80 PLUS Platinum efficiency, reaching up to 94%. This provides lots of benefits for your high-end system, including less power consumption and an overall cooler and quieter operation. The standby drain is below 0.1 watts.

Silent Wings 3 Fan

Provides virtually inaudible operation

The high-end Silent Wings 3 fan delivers best-of-class airflow yet produces very little noise. This is thanks to its unique, optimized fan blade design along with an advanced fluid-dynamic bearing and 6-pole fan motor that largely eliminates operational noise, has a super-long life and minimal power consumption.

Funnel-Shaped Fan Opening

Higher cooling performance

The fan inlet of the Straight Power 11 Platinum 850W is funnel-shaped. It causes an increased throughput of air which benefits to a higher cooling performance.

Wire-Free Design Inside the PSU

Pushing the longevity of components to a maximum

An absolute innovation: The Straight Power 11 Platinum 850W is wire-free on the DC side inside the PSU body. This results in improved cooling airflow and less signal disturbance, simply because of a lack of wiring, and ultimately pushes the lifetimes of the components to a maximum.

Modular Cables

Utmost convenience and compatibility

Thanks to the modular cables, all cables that serve no purpose in the system are left out. For this reason, systems always appear very tidy. At the same time installation is performed much more conveniently. A smoother airflow results from the uncluttered layout of the system, which means lower noise and temperatures prevail inside the case.

State-of-the-Art Technologies

Rock-steady signal stability and efficiency

Experience the most technologically advanced power supply be quiet! has ever built! Using an advanced full bridge, LLC and Synchronous Rectifier (SR) technology it provides unmatched signal stability and unbeatable power efficiency. The DC-to-DC conversion for tight voltage regulation, even under heavy cross-loading conditions ensures reliable operation for the next generation of processors and graphics cards.

Japanese 105 Capacitors

A testament to high quality

Only the best components are used in Straight Power 11 Platinum 850W. That is why we have built only high-quality Japanese capacitors into the PSU chassis. They are rated to 105°C, ensuring stability, reliability and a long operating life.

Form Factor



Be Quiet! Straight Power 11


Fully Modular


ATX 12V 2.51 & EPS 12V 2.92


850 W


1 x 4+4-pin CPU +12V (EPS)
1 x 4-pin FDD Power
4 x 4-pin Molex
4 x 6+2-pin PCIe
1 x 8-pin CPU +12V (EPS)
11 x SATA

Rail Design

Quad Rail

AC Input

AC 100-240 V


Active PFC

Fan Type

Silent Wings 3 135mm fan (fluid-dynamic bearing)

Fan Bearing

Fluid / Hydraulic Bearing


dB(A) at 20% load: 7.7
dB(A) at 50% load: 7.9
dB(A) at 100% load: 22.0

80+ Certification

80+ Platinum


Up to 94%


100,000 hours


Over current
Over voltage
Under voltage
Short circuit
Over temperature
Over power


1.84 kg
150 x 170 x 86 mm

Delivery Options

Next Day Delivery - £10

Can't wait to get your hands on your item.

Do you want to start gaming as soon as possible

Then this is the option for you. Order before midday, select this option at checkout and it will get to you the next working day

2 - 3 Days Delivery - £5

Are you a patient gamer.

Are you secure in the knowledge that your order will get to you at some point. Then select this option at the checkout and your order will arrive at your location in the the next two to three days.

Saturday Delivery - £15

Want to be there when your order arrives at your door.

Don't want to be at work all day knowing that your precious PC component is waiting for you to get home (unless of course, you work from home), then select this option and your order will delivered on the upcoming Saturday.

Click and Collect - FREE

If you're local to us, and would istead like to collect your order from our store, then this option is perfect for you. Not only is it free, but you can also choose when you would like to collect your order in hourly slots, Monday to Saturday. Just give us a couple of hours to get your order ready, and you will recieve a confirmation email telling you to pop on by.

Our store is open until 5:30pm Mon-Sat, so you have plenty of time after work to drop in.