Be Quiet! BL030 Silent Wings 2 PWM case fans (120mm) (Accessories)
Fan is extremely quiet, is with me as a CPU fan on an AIO-water cooler for a i5-4690. CPU remains at max. 62 ° C, and the fan is only max. ever heard. GPU and even the AIO water pump are more audible than the fan itself. Of course, care must be taken