Although the support for DirectX Raytracing is now available for Pascal, Volta-based Titan V, and non-RTX Turing graphics cards like GTX 1660 Ti and GTX 1660, you can't expect any miracles as, according to performance numbers released by Nvidia, those GPUs will have a hard time coping with those ray tracing effects.
For example, in Metro Exodus running at 1920x1080 resolution, even the GTX 1080 Ti won't be able to provide 30fps with Ultra DXR and Ultra Game settings. Even when DXR effects are lowered to High, the GTX 1080 Ti can barely push over 30fps. A similar thing goes for Shadow of the Tomb Raider, with GTX 1070 barely hitting over 30 fps at 1080p.
The situation is pretty much similar in all other tests, including Justice, Atomic Heart, and Reflections RTX tech demos, as well as the Battlefield V game, where only at medium DXR effects, you can get over 60fps on GTX 1080 Ti at 1080p resolution.
You can check out more performance details over at Nvidia's dedicated post, or check out this video in which Nvidia's VP of Technical Marketing, Tony Tamasi, explains a bit more about DXR and its implementations in games.
In addition to enabling DXR for additional Pascal GPUs, the new Geforce 425.31 Game Ready driver brings optimizations for Ubisoft's Anno 1800 game, and fixes seen in Adobe applications with SLI, random crashes on GeForce RTX 20 series GPUs in ARK Survival Evolved, issues with The Witcher 3, The Evil Within 2, and some other games, and a couple of other minor issues.
The Geforce 425.31 Game Ready driver is available for 64-bit Windows 7 and Windows 10 OS and supports all Geforce graphics cards since Geforce 600 series. You can download it from Nvidia's driver support page.