Isn’t this highly reduces bandwidth for GPU? Also your motherboard have free SATA6 ports and PCIe 2.0 x1 slot. Could you please read my post because I think this might be relevant to you, though for now there’s no solution: [Problem] ReBAR / LargeBAR on LEGACY systems
Basically this platform has some locked capability for PCIe Large-BAR which unfortunately no one unlocked yet…