CORSAIR RM Series , RM650, Fully Modular Power Supply vs CORSAIR RM850e Fully Modular Low-Noise ATX Power

Overview of the Products

The CORSAIR RM Series and CORSAIR RM850e are both excellent choices for those seeking reliable power supplies. The RM Series, priced at $138.31, is a fully modular power supply from 2021, offering a solid performance with a focus on low noise. In contrast, the RM850e, available for $94.99, is a newer model from 2025 that emphasizes modern compliance and efficiency. This price difference of about 31% positions the RM850e as a more budget-friendly option for gamers and PC builders.

Power Efficiency

When it comes to power efficiency, both the RM Series and RM850e excel with 80 PLUS Gold certification. However, the RM850e stands out with its Cybenetics Gold efficiency rating, ensuring optimal performance with lower energy consumption. This means the RM850e not only provides steady power but also saves on electricity bills in the long run. While the RM Series is a reliable choice with solid electrical performance, the additional efficiency of the RM850e gives it an edge, especially for power-hungry setups.

Noise Levels

Noise output is a critical factor for many PC builders, and both power supplies aim for minimal sound. The RM Series features a 140mm rifle bearing fan designed to keep noise levels low, even under full load. In comparison, the RM850e incorporates a 120mm rifle bearing fan with a calculated fan curve to ensure quiet operation. While both units are designed for low noise, the RM850e's newer technology and design may offer slightly better performance in maintaining silence during operation, particularly during lower loads.

Cable Management

Cable management is simplified with both the RM Series and RM850e, thanks to their fully modular designs. This feature allows users to connect only the cables they need, reducing clutter within the PC case. The RM Series includes triple EPS12V connectors, making it compatible with modern graphics cards and motherboards. On the other hand, the RM850e introduces a native 12V-2x6 connector that supports the latest PCIe 5.1 platform, accommodating next-gen GPUs and providing better performance during power excursions. This slight advantage in connectivity makes the RM850e more future-proof for enthusiasts.

Warranty and Reliability

Warranty length can be a telling factor in a product's reliability. The RM Series boasts a ten-year warranty, indicating a strong commitment to product longevity and customer service. On the contrary, the RM850e offers a seven-year warranty, which, while still generous, is shorter than that of the RM Series. Both units are built with industrial-grade, 105°C-rated capacitors, ensuring dependable performance. However, the longer warranty period of the RM Series could provide additional peace of mind to users who prioritize durability.

Modern Features

The RM850e comes with modern features that make it well-suited for contemporary builds. Its compliance with ATX 3.1 and PCIe 5.1 standards means it can handle the latest graphics cards and their power requirements efficiently. Additionally, the RM850e supports a modern standby mode, providing quick wake-from-sleep times that enhance user experience. Conversely, the RM Series, while still a competent power supply, lacks these modern capabilities, which could be a drawback for users looking to future-proof their setups.

Size and Compatibility

Both power supplies are designed to fit in a variety of cases, but the RM850e's 140mm casing provides a slight edge in versatility. The shorter length of the RM850e makes it easier to install in tighter spaces, accommodating a broader range of PC cases. The RM Series, with its similar dimensions, also fits well in most setups, but the more compact design of the RM850e may appeal to those with space constraints.

Which should you buy?

Choosing between the CORSAIR RM Series and CORSAIR RM850e ultimately depends on your specific needs and budget. If you prioritize a longer warranty and a proven track record for reliability, the RM Series may be the better choice for you. However, if you're looking for modern features, enhanced efficiency, and a more budget-friendly price point, the RM850e stands out with its compliance to the latest industry standards and lower price of $94.99. Overall, the RM850e offers more contemporary advantages, making it an excellent option for new builds or upgrades.