be quiet! System Power 11 550W ATX 3.1 PCIe 5.1 PSU
be quiet!
be quiet! System Power 11 550W ATX 3.1 PCIe 5.1 PSU
The be quiet! System Power 11 550W ATX 3.1 PSU is built for value-conscious PC builders who want reliable power delivery and quiet operation without compromise. It supports the latest PCIe 5.1 GPUs and meets modern efficiency standards, making it suitable for mid-range gaming and productivity builds.
Why this product
ATX 3.1 and PCIe 5.1 ready
Supports one PCIe 5.1 12V-2x6 connector for next-gen high-end GPUs, plus three additional 6+2 pin connectors for flexibility.
Temperature-controlled 120mm fan
The fan adjusts speed based on load, keeping noise down during light use and ramping up only when needed.
Strong 12V rail for stability
Tight voltage regulation using DC-to-DC technology ensures rock-solid power delivery to demanding components.
80 PLUS Bronze efficiency
Achieves up to 90% efficiency at 230V, 20% load, reducing wasted energy and heat generation.
5-year manufacturer's warranty
Backed by a lengthy warranty and designed, manufactured and quality-controlled in Germany.
- Continuous power550 W
- Certification80 PLUS Bronze
- ATX standard3.1
- PCIe GPU supportPCIe 5.1
- Warranty5 years
- Dimensions150 × 140 × 86 mm
- SKUBEQ-714
- EAN4260052191866
- Supports ATX 3.1 standard motherboards and PCIe 5.1 graphics cards with 12V-2x6 connectors.
- Works with GPUs requiring up to three 6+2 pin connectors for multi-GPU or high-power single-GPU setups.
- Fits standard ATX chassis with dimensions of 150 × 140 × 86 mm.
- Requires 200–240V AC input at 50 Hz; verify mains voltage availability in your region.
Best for
- Mid-range gaming and productivity builds
- Quiet system builds where noise control matters
- Builders prioritising reliability and warranty coverage
- Future-proofing for PCIe 5.1 GPUs without paying for excessive capacity
Trade-offs
- High-end enthusiast builds — 550W is the maximum continuous output; systems with dual high-power GPUs or high-core-count CPUs will need more headroom.
- Extremely power-hungry workstations — peak power specification is not published; this unit targets stable, predictable loads rather than systems with spiking demands.
- Fanless or silent-first builds — the 120mm fan is temperature-controlled but not eliminated; systems requiring no audible cooling should consider passive designs.
System Power 11 is the ATX 3.1 PSU for value-oriented PC builders that do not want to pass on reliability and quietness.
General
| Brand | be quiet! |
|---|---|
| Model | System Power 11 550 W |
| Form factor | ATX 3.1 |
| EPS 12V standard | Version 2.92 |
Power delivery
| Continuous power output | 550 W |
|---|---|
| 12V rail topology | Double forward + DC-DC |
| Power factor at 100% load | >0.98 |
| PCIe 5.1 connectors | Up to 1 × 12V-2×6 (600W) |
| PCIe 6+2 connectors | Up to 3 |
Efficiency & environmental
| 80 PLUS rating | Bronze |
|---|---|
| Efficiency at 20% load | 88.6% |
| Efficiency at 50% load | 89.7% |
| Efficiency at 100% load | 86.6% |
| Modern standby mode | Yes |
| Standby drain | <0.15 W |
Cooling & reliability
| Fan type | 120mm temperature-controlled |
|---|---|
| Input voltage range | 200–240V AC |
| Input frequency | 50 Hz |
| Warranty | 5-year manufacturer's warranty |
| Design & manufacture | Germany |
Shipping
All our products are shipped from the United Kingdom within 24 to 48 hours of purchase. See our Shipping and Returns page for full details.
Returns
- Tech Syndicate offers a full money-back guarantee on all purchases made in our store. If you are not satisfied with your purchase, we will provide a full refund, no questions asked.
- Refunds are available within 45 days of delivery.
- After the 45-day period you are no longer eligible for a refund, so we encourage you to try the product within the first few weeks to make sure it fits your needs.