TUNED FOR LOW-NOISE OPERATION RMx power supplies are tuned with a low-noise fan curve to ensure that even at full load fan noise is kept to a minimum. 80 PLUS GOLD CERTIFIED The RM550x can deliver power with over 90% efficiency to keep energy consumption noise temperatures and your power bill low. COMPACT SIZE The RM550x’s 160mm-long casing ensures an easy fit in almost all modern enthusiast PC cases. FULLY MODULAR CABLES The RM550x’s fully modular power cables mean that you only connect the cables your system needs making clean and tidy builds easier. .