I'm not saying you shouldnt pay attention to your cpu temps. However, fluid temps increase a lot under load. For me my water idles in the 30-32c area depending on ambient. Moment everything gets loaded this can go up to 46c if the fans are doing nothing or near it. As the example I gave before. Since speedfan doesn't work with x370. Assuming your whole pc is on water. f I were to set my fan control based on the cpu, in games my gpu would just get hotter and hotter since the cpu is often seeing very little load and temp increase. While an increase in load on the gpu or cpu will raise fluid temp.