In the Google or Graphics card official website you can see there is recommend PSU for Graphics card. Most of the new user get confused about this. Is recommended PSU correct or not ?
For GTX 1060 use 120 watt power and the recommended PSU is 400 watt. An average Computer system take only 200 watt or less and the GPU takes 120 watt so totally it takes 310-320 watt and the PSU can give 320 watt. How ever if any CPU consume 100 watt like I7 or I9 or Ryzen 7 or 9 then this recommended PSU will not work and even you don't have high end power consume CPU but you have to much fan or AIO or to much SSD and HDD then you recommended PSU will not work. If you are thinking then why they post the recommended PSU because a minimum 400 PSU can give at least 120 watt through out the PCIe power cable and the system only 150-200 watt so If your buying a PSU for GPU then calculate the full system power consume then decide which PSU and GPU is good for you