Performance, Performance Per Dollar, Noise and Efficiency Ratings
The following graph shows the total performance rating of the PSU, comparing it to other units we have tested. To be more specific, the tested unit is shown as 100 percent, and every other unit's performance is shown relative to it.
Corsair's performance is very good. Only Seasonic's excellent SS-5220FL, which costs much more, manages to take a clear lead. The Platinum-rated Super Flower unit surpasses the RM550x mostly because of its higher efficiency. Most notably, Corsair successfully delivers a power supply in this category that beats the previously-dominant 550 G2.
Performance Per Dollar
The following chart may be the most interesting to many of you because it depicts the unit's performance per dollar score. We looked up the current price of each PSU on popular online shops and used those figures and all relative performance numbers to calculate the index. If the specific model wasn't available in the United States, we searched for it in popular European Union shops, converting the listed price to USD (without VAT). Note that all of the numbers in the following graph are normalized by the rated power of each PSU.
The RM550x's price isn't great, so its performance per dollar suffers. Corsair should drop this product's price by $10 or $15 if it wants to compete more aggressively.
The graph below depicts the cooling fan's average noise over the PSU's entire operating range, with an ambient temperature between 28 and 30 °C (82 to 86 °F).
This is hands-down the quietest 550W PSU we've ever evaluated.
The following graph shows the average efficiency of the PSU throughout its entire operating range, with an ambient temperature between 28 °C and 30 °C.
In our normal efficiency tests, the RM550x scored high. But in the cross-load tests, where thousands of load combinations are dialed in, the unit falls behind its competition. The difference isn't significant though, and the fact is that the small RMx model is still considered highly efficient.