You can probably get a toggle off/on going though a powershell script like so.

- Open Windows Powershell ISE and copy paste the following code into it

    {
    
    #Disable the GPU
    
    Get-PnpDevice -FriendlyName "GPU NAME" | Disable-PnpDevice
    
    #Adjust wait time to any amount you want
      
    
    Sleep -Seconds 5
    
    #Enable the GPU
    
    Get-PnpDevice -FriendlyName "GPU NAME" | Enable-PnpDevice
    
    }

- Replace "GPU NAME" with the exact name of your GPU as seen inside device manager. This is the "Friendly Name". Not all commands work with friendly name though so you might need to use the `-Deviceid` argument instead of `-FriendlyName` and retrieve the Deviceid by right clicking > properties on the GPU inside device manager.

- Save the script to your desktop and right click > run with powershell

This should now toggle your GPU off/on. For other ways to clear the ram cache you'll have to check out the NVIDIA development forum. There are some things you can script with NVIDIA GPU's. A few sample scripts should be available for you to check out here on your local C Drive:

C:\Program Files\NVIDIA Corporation\NVIDIA WMI Provider\Samples