To turn your GPU ECC on or off
From the NVIDIA Control Panel Select a Task pane, under Workstation, click Change ECC state.
In the ECC column, check the check box of any GPU for which you want to turn On ECC, and clear the check box of any GPU for which you want to turn Off ECC.
Typically, depending on the GPU, you will need to restart your computer in order for the changes to go into effect. In this case a dialog appears to prompt you to restart your computer.
If you click Restart Later at the dialog prompt, then the relevant ECC check box will indicate that a restart is pending and the change is not yet in effect.