This article is pretty embarrassing, and as others have noted, very misleading due to the RTX units hardly being used.

This only runs on nvidia, vulkan is designed to be cross-compatible with not only gpus, but operating systems as well. Vulkan is pretty direct compared to something like dx11 thought so I guess it is interesting to see performance improvement non the less.

CUDA Ray Tracing 2x Faster Than RTX when Rendering Spheres

As far as I can see, this renderer can't do anything else except spheres (and maybe planes).

It's no bad achievement to beat a general purpose production renderer at one specific thing, but a renderer that can only do spheres is just a hyper-optimized toy, and here it's being presented as far more than that.

Ahh, my favorite nitpick from C++ not having sane default aliasing rules spills to the CUDA-land.