pintolcv I do not have a GTX 740 card so I can not test your condition. However it is my understanding that you would not need the Nvidia web downloaded drivers with this card.
And some of my newer systems I have both the on-board and external GPUs loading, but all of these only have displays attached to GPU card. One Chimera system, the Z97N-WiFi with a MSI GTX 760 ITX GPU experiences this "popping in" boot (no loading gage displayed). This one boots from an SSD and the boot is so fast that I have not felt the need to jack with it.
Good modding,
neil