CORSAIR RM850x Fully Modular Low-Noise ATX Power Supply vs CORSAIR SF850

Overview of the Corsair RM850x and SF850

The Corsair RM850x and SF850 are two high-end power supplies from Corsair, offering distinct features catering to different user needs. The RM850x, priced at £124.40, is a fully modular ATX power supply emphasising low noise and efficiency. In contrast, the SF850, retailing at £149.99, is a compact SFX power supply that combines high performance with space-saving design. Both products are ATX 3.1 compliant, demonstrating their modern capabilities in handling the latest hardware demands.

Design and Form Factor

The RM850x features a standard ATX form factor, making it suitable for a wide range of cases, while the SF850 adopts a compact SFX design ideal for small-form-factor builds. This difference in form factor is crucial for builders with limited space. The SF850’s smaller size allows it to fit into tight environments, making it a top choice for mini-ITX systems. Conversely, the RM850x’s larger dimensions provide ample space for cabling and cooling, appealing to users seeking a traditional build with more room for airflow.

Power Efficiency

Efficiency is a key consideration when selecting a power supply, and here the RM850x shines with its Cybenetics Gold certification, boasting an efficiency rating of up to 91%. This level of efficiency not only leads to lower energy consumption but also results in reduced noise and cooler operating temperatures. On the other hand, the SF850 offers an even higher performance with its 80 PLUS Platinum rating, indicating superior efficiency than Gold-rated models. The SF850 is designed for users prioritising maximum power efficiency, particularly in demanding setups.

Modular Connectivity

Both the RM850x and SF850 are fully modular, allowing users to connect only the cables they need for their systems. The RM850x is equipped with embossed cables featuring low-profile combs for streamlined installation. This design enhances the aesthetics and manageability of cable routing. Meanwhile, the SF850 utilises Type-5 Micro-Fit connectors, which not only save space but also simplify cable management in compact cases. This modularity is essential for users who desire a neat and efficient build, particularly in small form factors.

Cooling Solutions

Cooling performance is vital for maintaining system stability, and both power supplies incorporate advanced cooling solutions. The RM850x benefits from a design that prioritises low-noise operation, making it an excellent choice for quiet builds. In contrast, the SF850 features a 92mm PWM cooling fan designed to provide effective cooling while remaining quiet during operation. This thoughtful engineering ensures that both power supplies maintain optimal temperatures, although the SF850 may have an edge in smaller builds where airflow can be more constrained.

Compatibility with Modern Hardware

Both the RM850x and SF850 are compliant with the ATX 3.1 power standard, which allows them to support the latest PCIe 5.1 graphics cards. This compliance ensures that users can confidently pair either power supply with cutting-edge hardware without concerns about compatibility. The RM850x includes a native 12V-2x6 connector, which simplifies connections for modern GPUs, eliminating the need for adapters. This feature is particularly beneficial for enthusiasts building high-performance gaming rigs or workstations.

Pricing and Value

In terms of pricing, the RM850x is more affordable at £124.40 compared to the SF850's £149.99. Given the significant price difference, the RM850x presents an attractive option for users seeking reliable performance without breaking the bank. However, the higher cost of the SF850 may be justified for those who require a compact power supply with superior efficiency and advanced features. Ultimately, the choice between the two can depend on the user’s budget and specific needs.

Which should you buy?

Choosing between the Corsair RM850x and SF850 ultimately depends on your specific requirements and build considerations. If you need a cost-effective, fully modular ATX power supply with excellent efficiency and low noise, the RM850x is an excellent choice at £124.40. However, if your focus is on a high-efficiency compact power supply that fits into smaller builds while offering advanced cooling and modularity, the SF850, priced at £149.99, is the way to go. Both power supplies represent Corsair's commitment to quality, but your final decision should reflect your individual needs, budget, and intended use case.