Dude, if I keep looking at your Avatar I will never get my work done. Way too distracting man. What I get for being an early adopter/adapter, this has been an issue all along with the H100s, so chances are you will receive a quiet unit. My current H100s pump has RPM'ed out of tolerance a few times since purchased in April this year, but nothing that a nice soft tapping on the pump unit wouldn't clear up. It only happens when snapping the right-hand chassis door closed, but is easily taken care of. Others have not been as lucky and the simple tapping does not take away the awful grinding, those enthusiasts have relied on the RMA system and some receiving faulty units as replacements, dear God what a nightmare.