https://www.cnet.com/news/nvidia-brings-a-little-rtx-directx-ray-tracing-to-gtx-graphics/

The Volta-based Titan V and Turing-based GTX 1660 and 1660 TI are also supported. But, before you get too excited, know that the cards will only support basic ray-tracing effects and low ray counts. The level of support will be dependent on the game, the graphics card model and game resolution, said Justin Walker, product manager for GeForce desktop GPUs. 

GTX cards will be able to handle basic single effects such as shadows or reflections. More complex lighting or multiple, simultaneous effects like the global lighting used in Metro Exodus will require an RTX card, Walker said. DLSS (Deep Learning Super-Sampling), another RTX technology, isn't supported either, which uses cloud-based AI to simulate games at higher resolutions and teaches your GPU how to mimic that level of detail.