If you use Forge, you cannot use Iris directly. Instead, you use Oculus , which is an unofficial Forge port of Iris. It is designed to work with Rubidium (a Forge version of Sodium) to give you the same performance boost.
In the world of Minecraft shaders, one name has consistently sat at the top for cutting-edge visuals: . It revolutionized Minecraft by introducing real-time Path Tracing (Ray Tracing) without requiring an RTX graphics card. seus ptgi iris compatibility oculus forge top