video2x switches to internal GPU as soon as starting to upscale extracted frames

[kngfbng]

Trying to upscale a 720p video sample using RealSR NCNN Vulkan in the GUI.

I set GPU ID to 1 (GTX 1050 Ti) in video2x.yaml and confirmed it is set to 1 in the Driver Settings (I made sure to be in the RealSR tab). While extracting frames, CPU usage goes to almost 100% and GPU 1 hovers around 10% usage by Video Decode:

The moment the video2x console shows "[+] INFO: Starting to upscale extracted frames," it stops using the dedicated GPU at all and starts using 100% of the internal GPU by 3D:

I set video2x.exe, video2x_gui.exe, ffmpeg.exe and realsr-ncnn-vulkan.exe to use the dedicated GPU in both the NVIDIA Control Panel and Windows 10 Graphic Settings and tried running video2x as administrator. It never touches the dedicated GPU at all, let alone CUDA, and upscale is unsurprisingly glacially slow.