For my usage: 5 hard drives, SSD 1, all takes place very simply and quickly. No whistling or squealing, hardware is excellent (careful not to screw up the screw for the graphics card by cons ...) and I'm satisfied. I frequently replace hard drives for backups, everything is done simply and without screws, using PROVIDED racks for this purpose. I do not use optical drive but I think the sound is also isolated to the front door. I do not use the adjustment to vary the speed of ventialteurs (3 positions): I think it is too gadget, I still prefer the management ventilos PWM since the OS.