Am running a Dell OptiPlex 7040, with Radeon R7 350X graphics card, DP output. Windows 10. Using a DP to HDMI cable to an LG 49UH610A "smart TV" (HDMI input). Windows 10 only loads default PnP drivers for the display. Cannot get high resolution with that! How do I tell Windows 10 to "see" the LG display? Do I need a DP to HDMI converter? Different drivers? What?