My system doesn't run shaders well with this mod, despite being plenty powerful. It also doesn't scale well at all, with "potato" shaders often running about the same as extreme ones. Performance on Sodium with shaders disabled is fantastic, and Optifine not only provides better shader performance but also scales better with different shader intensities.

System specs:

CPU: Ryzen 7 5800X
GPU: RX 6750 XT
RAM: 32GB DDR4 3800MHz
Storage: NVMe SSD

Is the mod just not designed to run well with AMD GPUs? I looked at the supported hardware on the website, and it does say AMD is supported, with just a few incompatibilities. Nothing is mentioned about terrible performance.

There seems to be a bug as of now where Iris 1.6 and up has horrible performance on some AMD drivers. This does not happen on Linux or NVIDIA cards.

There seems to be a bug as of now where Iris 1.6 and up has horrible performance on some AMD drivers. This does not happen on Linux or NVIDIA cards.

It does seem to happen on older versions of Iris though. If it's a driver issue then it's probably independent from the Iris version.