Introduction
The be quiet! Straight Power 11 850W represents the German manufacturer's latest iteration of their popular Straight Power series. Known for their emphasis on silent operation, be quiet! has built a reputation for delivering power supplies that live up to their name while maintaining excellent performance standards.
This 850W unit features 80 PLUS Gold certification, fully modular cabling, and be quiet!'s signature SilentWings fan technology. At $159.99, it positions itself in the premium segment, competing with offerings from Corsair, EVGA, and Seasonic. But does the Straight Power 11 justify its premium positioning?
Design and Build Quality
The Straight Power 11 features a clean, minimalist design that emphasizes function over flash. The unit's matte black finish and subtle branding create a professional appearance that will blend seamlessly into any build. Dimensions are standard ATX at 150mm x 86mm x 160mm, ensuring compatibility with most modern cases.
Build quality is immediately impressive. The chassis feels substantial and well-engineered, with no flex or cheap materials evident. The unit's weight distribution suggests high-quality internal components, and the modular cable connectors feel secure and well-fitted.
SilentWings Fan Technology
The 135mm SilentWings fan is the centerpiece of be quiet!'s noise reduction strategy. This fluid dynamic bearing fan operates with exceptional smoothness and remains virtually silent under normal loads. The fan's operation is so quiet that users often question whether it's running at all during typical usage scenarios.
Fan curves are intelligently programmed, with the fan remaining off until approximately 30% load. Even under moderate loads, fan speeds remain minimal, contributing to the unit's exceptional acoustic performance.
Performance Testing
Our comprehensive testing protocol evaluates efficiency, voltage regulation, ripple suppression, and thermal performance across various load conditions. The Straight Power 11 demonstrated exceptional performance in all categories.
Voltage Regulation Excellence
Voltage regulation is outstanding across all rails. The +12V rail maintained regulation within ±0.8% under all load conditions, significantly better than ATX specifications. The +5V and +3.3V rails showed similarly impressive regulation, with variations well under 1%.
This level of voltage stability indicates exceptional internal component quality and circuit design. Such tight regulation is particularly important for high-end systems where component sensitivity to voltage fluctuations can affect performance and stability.
Ripple Suppression
Ripple suppression is exemplary, with measurements well below ATX maximums on all rails. Under full load, ripple remained under 15mV on the +12V rail and under 25mV on the +5V and +3.3V rails. These results place the Straight Power 11 among the best-performing units we've tested.
The excellent ripple suppression indicates superior filtering and high-quality capacitors throughout the unit. This contributes to system stability and can improve overclocking headroom on sensitive components.
Noise Performance
As expected from a be quiet! product, acoustic performance is exceptional. Under typical gaming loads (40-60%), the unit operates in near-silence. Even under full load testing, noise levels remained impressively low at approximately 28dBA measured at 1 meter.
The SilentWings fan's fluid dynamic bearing contributes to this exceptional acoustic performance. The bearing operates without the mechanical noise associated with traditional ball bearings, and the fan's aerodynamic design minimizes air turbulence.
Thermal Management
Thermal performance is excellent, with the unit maintaining safe operating temperatures throughout all testing scenarios. Internal temperatures remained well within safe limits even during extended full-load testing in a 25°C ambient environment.
The intelligent fan control system ensures optimal thermal management while maintaining acoustic performance. The fan's gradual speed increases prevent sudden noise spikes while ensuring adequate cooling under all conditions.
Real-World Performance
In real-world testing with a high-end system (AMD Ryzen 9 7950X + RTX 4090), the Straight Power 11 delivered flawless performance. System stability was never compromised, and the unit handled the RTX 4090's notorious power spikes without issue.
The 850W capacity provides adequate headroom for most single-GPU configurations, including high-end processors and graphics cards. Users planning dual-GPU setups should carefully calculate their power requirements, though the unit's excellent efficiency and stability make it suitable for such configurations.
Modular Cable System
The fully modular cable system is well-designed and user-friendly. All cables, including the 24-pin motherboard connector, are detachable, allowing for excellent cable management. Cable quality is excellent, with flat ribbon-style cables that are easy to route and manage.
Cable lengths are well-considered, providing adequate reach without excessive slack:
- 24-pin motherboard: 600mm
- 8-pin CPU: 650mm
- 6+2-pin PCIe: 650mm + 150mm
- SATA: 500mm + 150mm + 150mm
- Molex: 500mm + 150mm + 150mm
