Help with gpus in linux needed

I dont know if this is the right post category but im having some trouble with my gpus on ubuntu.
I would like to use a graphics card that isn`t in slot pci slot one to drive my displays. however when i have a gpu plugged in to slot one i get terrible amounts of lag but if i take it out and just run the single card alone in slot four the performance is just fine. I also noted that when i ran it alone i had a new option for a driver install in the software menu.

here are the two cards in lspci
1b:00.0 VGA compatible controller: NVIDIA Corporation GK107GL [Quadro K600] (rev a1)
1c:00.0 VGA compatible controller: NVIDIA Corporation GM204 [GeForce GTX 970] (rev a1)
i would like to use the quadro for my monitors

Are you wanting to do pass through?

Yes that is the end goal. But right now im just trying to get things running on the quadro.

Since my first message was a little rushed I might want to explain what i`m trying to do.

I would like to use the quadro as the gpu for the host OS and the 970 for the vm. However i get really bad lag if i run my monitors off the quadro with both in the system.

Attempting to install drivers for the quadro renders me unable to boot, however if i run the system with just the quadro it works just fine and i am given a different option for the driver install which doesn`t render the machine unbootable.

Since you have two. I will close this one.