Managed to get GPU pass through working on my Dell R720 using a Nvidia tesla K80. Had to enable all virtualization options in the bios: VT-d, SR-IOV, also above 4G memory. As for a windows VM on proxmox installing with the UEFI bios option. Machine q35 added the pci device selecting all functions, ROM-Bar, and PCI-Express. After adding that I also downloaded the rom bios from https://www.techpowerup.com placed them into /usr/share/kvm/. Then modify /etc/pve/qemu-server/###.conf (### is the VM id number) under the hostpci line that has the video card listing add romfile=romfilename.rom that was downloaded in the previous step.