Clean map. Last forge last ir. Have same issue on clean world, clean modpack. Unknown entity spawn on bedrock level. Invisible.

That's the IR MagicEntity. It forces pretty much anything from IR in the world to render. It's supposed to be there. What are your system specs? That can be a much bigger factor.

That's the IR MagicEntity. It forces pretty much anything from IR in the world to render. It's supposed to be there. What are your system specs? That can be a much bigger factor.

i5-4690k 3,5 GHz 16GB RAM GTX1060. Maybe optifine issue?

Possibly, certain settings on Optifine mess with IR. Just curious, which IR resource packs do you have installed?

Narrow Gauge Goddies only

Are the FPS drops random?

Are the FPS drops random?

Yep. Entity sometimes dissapear (or going down in list), and drops with him) I'll try to launch withot optifine and send reply.

That was optifine issue. Thank you for anwsers. I'm just deleted optifine, and all fine. ^^