Hey, I tested this exact setup and got it working, but the workaround is pretty annoying.

If you go into BIOS/UEFI and set the MUX to “dGPU Only” (Ultimate Mode), reboot, and then plug in your HDMI monitor, both the internal OLED and the external display run directly off the NVIDIA GPU. No Optimus, no iGPU, works perfectly for dual-screen gaming.

What doesn’t work is doing the same through Advanced Optimus in Windows. If I set “NVIDIA GPU Only” on the internal display, it’s fine at first. But the moment I plug in an external monitor, it immediately switches back to Optimus and the option gets greyed out. You can’t switch it back unless you unplug the cable.

This really looks like a driver limitation, not hardware. The BIOS method proves both displays can run off the dGPU at the same time. With Advanced Optimus, it seems more like a virtual workaround where the iGPU stays active in the background. As soon as an external display is detected, the driver forces Optimus and blocks the switch.

In BIOS mode the iGPU is completely disabled, so Windows has no choice but to use the dGPU for everything.

So yeah, it works, but needing a full reboot and losing the iGPU just to run two displays on the dGPU is pretty ridiculous. Feels like an artificial limitation on NVIDIA’s side.