Power supplies are often overlooked, yet extremely important parts of a PC. Some won’t appreciate a reliable power supply with working safety features, until they have one fail in the middle of a heated gaming session. Ideally, after building a PC, you do not want to have to worry about your power supply anymore for a few years, even when other components like motherboard, CPU or graphics card are upgraded. With warranties up to 10 years, they can be a loyal and trusted companion; quietly and reliably carrying out their job.
Part 1: Technology
When choosing a power supply, there are several features to consider. You should treat this as a guideline and select which parts matter most for you personally.
- Cables and connectors
- Cooling and noise
- Form factor
- Topologies and 12V rails
Cables and connectors
Most PSUs with certain wattages come with the appropriate cables for typical graphics cards and CPUs you would build into a PC with the rated power. However, taking a second look whether all needed cables are provided, does not hurt. This becomes especially important with 12VHPWR connectors if you do not want to use adapters for newer graphics cards.
Most power supplies these days also come with modular cables, meaning you only connect the cables that you need. This gives you more room and flexibility for cable management because less cables clutter the limited space. Modular cables can also be replaced easier with sleeved custom cables.
To dive deeper into the topic of different PSU cables, check out this video :
Cooling and noise
A good PSU cooling concept is important to increase the component lifetime and reduce chance of failure after years of operation. Our high-quality fans are optimized to provide excellent cooling and often with very low starting RPM to make sure the necessary cooling of the power supply does not go on anybody’s nerves in low-load conditions.
Most desktop cases fit ATX form factor power supplies. This standard defines the height at 86mm and width of the PSU case at 150mm, but you should always check the maximum supported length of your case, as this may vary from PSU to PSU.
Smaller form factors like SFX (or SFX-L) and TFX are common for very compact PCs.
Certain protection circuits for over voltage (OVP), under voltage (UVP), over power (OPP), over current (OCP) and short circuits (SCP) are required by the ATX design guide. We include the non-mandatory over temperature protection (OTP) in all our power supplies as well, adding another safety layer. These protections cut the power to all components if any of the trigger points is tripped. Usually, if no catastrophic component failure triggered the safety, the PSU can be turned on again after a short while. However, this should not be done before having the cause investigated by a professional.
Topologies and 12V rails
When building a power supply, brands can choose between different technologies to achieve the power conversion from alternating current from the wall socket to direct current on 12V, 5V and 3.3V , which is used by a computer’s components. We break down the details in a different article.
You also need to decide between a multi-rail and single-rail power supply. Multi-rail models will have two or more 12V rails, with specific assignments which rail is responsible for the CPU, GPUs, hard drives and so on. Each rail can be secured with their own over current protection, reducing the risk of high currents and potentially melting cables in case of a failure. Single-rail power supplies work better in extreme overclocking scenarios and are generally care-free, as the user does not have to waste a thought where to connect which PCIe cable.
Some models, like the Dark Power Pro 13, even come with extremely precise digital regulation, single-sleeved cables and a high-grade aluminum case.
Part 2: Different use cases require different power supplies
ATX 3.0 power supplies
If you are building a completely new future proof PC, we recommend setting yourself up with a ATX 3.0 power supply. They can handle the power spikes that PCIe 5.0 graphics card may exhibit. Another good reason for an upgrade is to avoid using an adapter, if you own a PCIe 4.0 graphics card with 12VHPWR connector. The following series are fully compatible with the ATX 3.0 standard.
Multi GPU power users
While multi GPU setups are not supported anymore by most modern games , they are very useful in work stations that do a lot of rendering work. For these enthusiast users that may need more than 600 watts of PCIe power to run their setup, we offer models with two 12VHPWR connectors.
Enthusiast and esports gaming setups
Modern triple A games require plenty of processing power. Esports athletes also benefit from powerful systems that allow smooth game play and high frame rates. Average component power draw has increased over the last years. We offer solutions for everyone throughout all efficiency levels from 80 PLUS Gold up to Titanium. A typical system in this range could consist of an AMD Ryzen 7950X or Intel i9 13900K CPU with Nvidia GeForce RTX 4090 graphics card.
Casual gaming setups
For these users, be quiet! provides you with the perfect matching PSU, whether you want a Dark Power, a Straight Power or a Pure Power. All work great with a typical system that incorporates an AMD Ryzen 7800X3D or Intel i5 13600K CPU with Nvidia 4070 or AMD Radeon RX 7600 graphics card.
Small form factor models
While many small form factor cases fit ATX power supplies, if you want to go really small, you may need a small form factor power supply. The most popular are SFX (Small Form Factor), or SFX-L, and TFX (Thin Form Factor). SFX-L is not an official form factor, but indicates a higher depth, usually to fit a larger and more efficient cooling fan and high-performance components for higher power. They are, for example, used to power a small gaming system with a mid-range CPU and graphics card, while the lower wattage SFX and TFX variants are often used in conjunction with a low-power CPU with integrated graphics unit.
If you found out what matters most to you, the next step would be to find a power supply that checks all of your boxes. For that, we recommend our PSU calculator. It assumes the maximum specified power draw for the entered components and adds power budget for overclocking, if selected. The tool takes the supplied cables into account as well and is completely transparent.