I had to make an account just to reply to this thread. There are very few mods that I would consider must-haves for a modpack, but fastcraft just instantly made my list. I went from constant stutters and 5 second freezes with fps constantly below 20, to buttery smooth just by installing this mod. FPS never dips below 50 now. It's like I just spent two grand building a computer optimized for minecraft. Thank you so much Player, I can't say enough how amazing this mod is.