I would say that it depends upon your situation. I consider the noise the biggest downside to leaving the fans at 100 percent. My Intel motherboard, with the fan control set to auto runs the fans too slow in my opinion. The CPU fan doesn't start speeding up until the cores reach 70C. A little to high for me. So, I have the fan speeds set manually at about 75 to 85 percent. The core temp stay lower and I'm happy. A little more noise, but not as much as 100%. If noise wasn't a factor, I would run the fans at 100%.