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If your be quiet! power supply has become noticeably noisy, identify its exact model and check its warranty before doing anything else. For an in-warranty fan problem, be quiet! directs owners to its service staff. The company also says it cannot support repairs that require opening the power supply, so do not attempt an internal fan replacement.
First, check whether the sound matches your PSU’s design
Fan behavior differs by power-supply model. be quiet!’s FAQ describes active PSU fans as running continuously, while the Power Zone 2 850W uses semi-passive cooling: its fan can stop at low load and continue running for a short cooldown after load falls. A fan that runs—or briefly keeps running—does not by itself establish a fault. Check the manual or product information for your exact model rather than applying one model’s behavior to the whole brand.
What the published specifications say
The Power Zone 2 850W product page specifies a 140 mm fan, semi-passive operation, and 2–5 minutes of fan post-ventilation after load. be quiet! says the cooldown helps avoid frequent starts and stops. The same page lists up to 94.1% efficiency; that is an efficiency figure, not a noise measurement. See the Power Zone 2 850W specifications.
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Other be quiet! models publish their own acoustic figures. The SFX Power 3 450W page lists maximum fan noise of 33.8 dB(A), and the TFX Power 3 300W Bronze page lists 29.1 dB(A). Those figures apply to those models only. The published pages do not provide a controlled comparison across models, so they are not enough to rank the brand’s PSUs by quietness. SFX Power 3 450W specifications · TFX Power 3 300W Bronze specifications.
#1 Best Overall
- 80 PLUS GOLD CERTIFIED Pure Power 13 M 850W is certified 80 PLUS Gold with an outstanding efficiency rating of up to 94.4%. The most compelling benefit: lower power consumption, consequently lower costs, and above all a cooler as well as quieter operation. Pure Power 13 M 850W is always the correct choice for quiet systems and gaming PCs!
- FUTURE-PROOF YOUR SYSTEM Pure Power 13 M 850W is an ATX 3.1 PSU and comes with both native integration of the 12V-2x6 connector for next-generation PCIe 5.1 graphics cards, and 4 PCIe 6+2-pin connectors for support of current-gen GPUs. This makes the PSU extremely versatile and the perfect choice for powerful systems of today and the ones to come
- THE NEW STANDARD OF POWER Pure Power 13 M offers 850W of continuous power with one massive 12V rail. Even if the graphics card demands excessive power for a short time: Pure Power 13 M 850W handles power excursions up to double its rated power with ease. This ensures reliable operation with the next generation of processors and graphics cards.
- SEMI-PASSIVE ZERO-RPM COOLING While under low load, the fan turns off completely until its services are needed again for more demanding operations. This feature, combined with the reliable be quiet! fan and its airflow-optimized fan blades, make Pure Power 13 M 850W exceptionally silent in all load scenarios
- HIGH-CLASS TECHNOLOGIES With its LLC topology Pure Power 13 M 850W provides best-in-class voltage regulation and efficiency. That makes it perfect for building very quiet systems or upgrading gaming and media creation PCs
Check warranty and contact be quiet! service
- Find the exact model and purchase details. Check the label on the PSU or your purchase records, then consult the model’s documentation and warranty information.
- Document the noise without opening the unit. Note when it occurs—for example, at startup, under load, or after load ends—and record a short clip if practical. This gives support useful context without attempting an internal repair.
- Contact be quiet! service if the warranty is active. The company’s FAQ says owners with a noisy fan should contact its service staff while the PSU remains under warranty.
be quiet! says: “For reasons of legal liability and technical insurance we are prohibited from supporting the independent repair of electrical appliances. This includes any actions that would call for you to break open the power supply.” Its FAQ also says, “Of course the fan should give you the same discreetly quiet performance for the whole of its warranty period.” These are the manufacturer’s statements; they do not diagnose the cause of noise in a particular unit.
Do not open the PSU to replace its fan
A fan swap inside a power supply requires opening the unit, which be quiet! says it cannot support as an independent repair. Do not treat a replacement fan as a routine DIY fix. If the PSU is out of warranty and remains unusually noisy, ask the manufacturer or a qualified repair provider about safe options rather than opening it yourself.
Rank #2
- 80 PLUS GOLD CERTIFIED Very high operating efficiency Pure Power 13 M 1000W is certified 80 PLUS Gold with an outstanding efficiency rating of up to 94.4%. The most compelling benefit: lower power consumption, consequently lower costs, and above all a cooler as well as quieter operation. Pure Power 13 M 1000W is always the correct choice for quiet systems and gaming PCs!
- FUTURE-PROOF YOUR SYSTEM Fulfills all ATX 3.1 specifications Pure Power 13 M 1000W is an ATX 3.1 PSU and comes with both native integration of the 12V-2x6 connector for next-generation PCIe 5.1 graphics cards, and 4 PCIe 6+2-pin connectors for support of current-gen GPUs. This makes the PSU extremely versatile and the perfect choice for powerful systems of today and the ones to come
- THE NEW STANDARD OF POWER For massive transient loads Pure Power 13 M offers 1000W of continuous power with one massive 12V rail. Even if the graphics card demands excessive power for a short time: Pure Power 13 M 1000W handles power excursions up to double its rated power with ease. This ensures reliable operation with the next generation of processors and graphics cards
- SEMI-PASSIVE ZERO-RPM COOLING Enjoy the silence While under low load, the fan turns off completely until its services are needed again for more demanding operations. This feature, combined with the reliable be quiet! fan and its airflow-optimized fan blades, make Pure Power 13 M 1000W exceptionally silent in all load scenarios
- HIGH-CLASS TECHNOLOGIES Rock-solid stability With its LLC topology Pure Power 13 M 1000W provides best-in-class voltage regulation and efficiency. That makes it perfect for building very quiet systems or upgrading gaming and media creation PCs
If replacement is necessary, check fit and behavior—not just the brand
A replacement PSU must match the needs and physical constraints of the computer. Before choosing one, check:
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A free scan shows the junk files, broken settings and background clutter dragging Windows down - then fixes them in one click.Free scan · Windows 10 & 11- Wattage and system needs: Select capacity for the components and required headroom, rather than assuming a higher-wattage unit is automatically suitable.
- Form factor: Confirm whether the case takes ATX, SFX, TFX, or another size.
- Connectors: Verify the power connectors required by the motherboard, graphics card, drives, and other components.
- Fan behavior: Look for active or semi-passive operation and read the exact model’s description of when its fan runs.
- Published acoustic information and warranty: Compare only specifications stated for the models you are considering, and check each model’s warranty terms.
The Power Zone 2 850W is one example of a semi-passive PSU; its product page lists a 140 mm fan and a 10-year manufacturer warranty. Those attributes do not make it a universal replacement: the right model depends on the computer’s power requirements, case, and connectors. Check its full specifications.
Rank #3
- 80 PLUS GOLD CERTIFIED Pure Power 13 M 750W is certified 80 PLUS Gold with an outstanding efficiency rating of up to 94.3%. The most compelling benefit: lower power consumption, consequently lower costs, and above all a cooler as well as quieter operation. Pure Power 13 M 750W is always the correct choice for quiet systems and gaming PCs!
- FUTURE-PROOF YOUR SYSTEM Pure Power 13 M 750W is an ATX 3.1 PSU and comes with both native integration of the 12V-2x6 connector for next-generation PCIe 5.1 graphics cards, and 4 PCIe 6+2-pin connectors for support of current-gen GPUs. This makes the PSU extremely versatile and the perfect choice for powerful systems of today and the ones to come.
- THE NEW STANDARD OF POWER Pure Power 13 M offers 750W of continuous power with one massive 12V rail. Even if the graphics card demands excessive power for a short time: Pure Power 13 M 750W handles power excursions up to double its rated power with ease. This ensures reliable operation with the next generation of processors and graphics cards.
- SEMI-PASSIVE ZERO-RPM COOLING While under low load, the fan turns off completely until its services are needed again for more demanding operations. This feature, combined with the reliable be quiet! fan and its airflow-optimized fan blades, make Pure Power 13 M 750W exceptionally silent in all load scenarios
- HIGH-CLASS TECHNOLOGIES With its LLC topology Pure Power 13 M 750W provides best-in-class voltage regulation and efficiency. That makes it perfect for building very quiet systems or upgrading gaming and media creation PCs
Do not assume modular cables are interchangeable
Modular PSU cables are not a noise fix. If you reuse or replace them during a PSU change, check compatibility by exact model and generation. be quiet! warns that pin assignments differ on some older units even when connectors physically fit; its FAQ explains the compatibility caution.
Quick Recap
Best Value
- PLATINUM CERTIFIED | Power Zone 2 850W is certified with 80 PLUS Platinum and Cybenetics Platinum, resulting in an energy efficiency rating of up to 94.1%. This results in lower power consumption, overall cooler and quieter operation, and many other benefits for your high-end system.
- SEMI-PASSIVE ZERO-RPM COOLING | A large Pure Wings 3 140mm fan is keeping Power Zone 2 850W cool. While under low load, the fan turns off completely until its services are needed again for more demanding operations. This post-ventilation requires a short cooldown period of 2-5 minutes to avoid frequent and annoying starts and stops of the fan. Combined with the large fan for active cooling, this power supply is exceptionally silent in all load scenarios.
- PURE WINGS 3 FAN | No Power Supply is like the other. Hence, we have altered aspects of our renowned Pure Wings 3 140mm fan to make it the perfect match for Power Zone 2 850W. The fan offers outstanding reliability and makes for a long-lasting companion. Due to its large diameter, the fan cools the interior of the PSU efficiently and quietly.
- FUTURE-PROOF YOUR SYSTEM | Power Zone 2 850W is an ATX 3.1 PSU and comes with both native integration of the 12V-2x6 connector for next-generation PCIe 5.1 graphics cards, and 3 PCIe 6+2-pin connectors for support of current-gen GPUs. A 90° angled 12V-2x6 connector in the scope of delivery leaves no doubt that this PSU is here to stay. All of this makes Power Zone 2 850W extremely versatile and the perfect choice for powerful systems of today and the ones to come.
- THE NEW STANDARD OF POWER | Power Zone 2 offers 850W of continuous power with one massive 12V rail. Even if the graphics card demands excessive power for a short time: Power Zone 2 850W handles power excursions up to double its rated power with ease. This ensures reliable operation with the next generation of processors and graphics cards.
Rank #4
- Dark Power 14 1200W is certified with 80 PLUS Titanium and Cybenetics Titanium for a stunning energy efficiency rating of up to 95.42%. This provides lots of benefits for a high-end system, including less power consumption and an overall cooler and quieter operation.
- Dark Power 14 1200W is an ATX 3.1 PSU and comes with both native integration of the two 12V-2x6 connectors for next-generation PCIe 5.1 graphics cards and 4 PCIe 6+2-pin connectors for support of current-gen GPUs. This makes the PSU extremely versatile and perfect for current and future high-end systems.
- A button on the rear of the power supply allows switching between a balanced active cooling mode, where the Silent Wings fan spins all the time, or a semi-passive mode, where the fan does not spin under low load and only starts when additional cooling is required for more demanding operations. A post-ventilation setting keeps the fan spinning after cooling down for a short period of 2–5 minutes to prevent frequent and noisy starts and stops.
- A large heat sink connects to the parts of the power supply that need the most cooling and dissipates a large portion of the heat. Even though a Titanium efficiency power supply does not generate as much heat, active cooling is required to prevent overheating issues under high load. Nothing less than the very best fan of be quiet! cools Dark Power 14 1200W. Being integrated directly into the heat sink, this high-end fan is immune to vibrations and sits unshakably. A 6-pole fan motor and fluid-dynamic bearing ultimately make for exceptionally long lifetime and minimal power consumption.
- Dark Power 14 1200W is particularly suitable for overclocking. With the simple push of a button, you can manually switch between multi-rail and single-rail mode. This gives you full overclocking control between the default four 12V-rail mode and the alternative massive single-rail operation.
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
