However, the performance will likely not be that great. NVIDIA says RTX GPUs do ray-tracing 2-3x faster:
NVIDIA GeForce GTX GPUs powered by Pascal and Turing architectures(1) will be able to take advantage of ray tracing-supported games via a driver expected in April. The new driver will enable tens of millions of GPUs for games that support real-time ray tracing, accelerating the growth of the technology and giving game developers a massive installed base.On a related note, real-time ray tracing will soon be integrated in both the Unreal Engine and Unity video game engines.
With this driver, GeForce GTX GPUs will execute ray traced effects on shader cores. Game performance will vary based on the ray-traced effects and on the number of rays cast in the game, along with GPU model and game resolution. Games that support the Microsoft DXR and Vulkan APIs are all supported.
However, GeForce RTX GPUs, which have dedicated ray tracing cores built directly into the GPU, deliver the ultimate ray tracing experience. They provide up to 2-3x faster ray tracing performance with a more visually immersive gaming environment than GPUs without dedicated ray tracing cores.