I've got this one too, but with nine 120mm fans instead of four 180mm fans. It's on a system with three 1080Ti and formerly a Broadwell-E, later Broadwell-EP. Some might remember this anecdote of mine: During a SETI Wow! Event, the plug which powered those nine fans accidentally detached. I didn't notice this at first, because the rig continued to run even without noticeable reduction of GPU clocks. And that was even though it was still as warm as typical for August in Germany.