Some settings of the Nvidia GPU influence greatly the rendering speed.
Here are some settings you should modify, for best rendering performance in Dragonfly.
-Open your Nvidia control panel, by right-click on your desktop and choosing "NVIDIA Control Panel".
If your global settings are configured to use the Nvidia GPU as follows:
you can then change the settings there directly, otherwise you need to change to the "Program Settings" tab, and find the Dragonfly executable settings (in our installation folder), making sure you select in the drop-down the Dragonfly_main.exe definition. You will need to repeat the same for 2 more executables: installation_folder\Python_env\python.exe and installation_folder\Python_env\pythonw.exe.
So in either case, you need to change the same settings, as shown here (the GPU will obviously differ from the screenshot, according to your GPU):
