"Raytracing not available" on RTX-capable device

[athyfr]

Opening either of the raytracing samples in GPUpad 2.6.1 yields disappointing results on my RTX-capable laptop.

It seems to think it can't do RTX, though I believe this worked fine in 2.4.0.

It doesn't seem to be logging anything relating to this.

System information (courtesy of KDE Info Center)

Operating System: NixOS 25.05
KDE Plasma Version: 6.3.4
KDE Frameworks Version: 6.13.0
Qt Version: 6.9.0
Kernel Version: 6.12.25 (64-bit)
Graphics Platform: Wayland
Processors: 32 × 13th Gen Intel® Core™ i9-13900HX
Memory: 16.4 GB of RAM
Graphics Processor 1: Intel® Graphics
Graphics Processor 2: NVIDIA GeForce RTX 4070 Laptop GPU
Manufacturer: Dell Inc.
Product Name: Dell G16 7630

I'm using the official (proprietary) NVIDIA driver.

[houmain]

Thanks for the report!
Is it possible to tell KDE which GPU an application should use? Maybe it is running on the Intel?
I will output the utilized GPU somewhere and add a warning when Vulkan is initialized on the integrated one.

[athyfr]

Is it possible to tell KDE which GPU an application should use? Maybe it is running on the Intel?

Although KDE doesn't have built-in integration with this, I'm able to override the GPU using environment variables:

export __NV_PRIME_RENDER_OFFLOAD=1
export __NV_PRIME_RENDER_OFFLOAD_PROVIDER=NVIDIA-G0
export __GLX_VENDOR_LIBRARY_NAME=nvidia
export __VK_LAYER_NV_optimus=NVIDIA_only

Doing that, the raytracing samples work, so I suppose it's running on the iGPU by default. (The new samples look nice!)