Ah thanks, I am using amd ryzen 7 5800x and I never touch those settings. System was fine for 1 year until I rma my gfx card and changed to another model 3080 that require more power than my old 3080. Not sure if my 750w PSU is unable to handle hence this issue?
the error you shown earlier is cause by CPU instead of GPU.
If your CPU in BIOS setting was on defaults then it could be due to windows that pushing the CPU utilization higher than necessary.
Do you monitor your CPU resource and thermal from time to time with utilities like HWiNFO?
Do take a look in take manager if you have a task name "widget" that somehow will increase the cpu resource for unknown reason, if you do notice this task please try to end task and see if your cpu will be cooling down further?
Take note also on other task which unknown to you are taking up the CPU resources.
As for the GPU 3080 when you mean more power required is it now from 2x 8 pin become 3x 8 pin?
if yes the it is best to have 3 pcie cable instead of piggy tail with 2 pcie cable.
750w on normal circumstances should be sufficient if it is a 2x 8 pin power 3080.
Also normally it is recommended using DDU to uninstall the old driver and reinstall a new driver when changing a new GPU.