having look at activity monitor, I realized today that MacFanControl (last version) consumed between 4 and nearly 10% of CPU ! First, I was paranoid and thought they would create bitcoins or something like that on their customers machines... but after stopping the process in activity monitor and restarting after that, MacFanControl uses just much less than 1% of CPU, mostly about 0,2-0,5 % - just as before. So, I stopped to get paranoid... So - have a look at your activity monitor and do just the same in case it consumes too much CPU resources. I remember similar problems with an original apple app before. But I don´t no which it was. might be the same or a similar bug, this time by a third-party developer. I am very thankful that MacFanControl exists - it helps me and other Users to protect the MBP´s GPUs to get too hot and die, if you alter apple´s useless standard-option for the fans and set the rpm of the fans higher at lower temperatures.