dell precision 5810

I have 1 NVMe SSD installed with the OS on it. I have a 2TB NVMe game drive in another system I want to install. I know the system supports 4x4x4x4 on the main PCI x16 slots. I can't find an answer anywhere regarding slot 1 which is PCIe 3.0 x16 running @ x8. Does anyone know if slot 1 will...