Phosphor is incompatible with Starlight. I won't get into the specifics but Starlight seems to be to more optimised lighting engine. Feel free to replace Starlight with Phosphor.

Why no Cull Leaves?

Another optimisation mod that I've not included in this pack is Cull Leaves. I personally just think how the leaves look is sorta ugly, and if necessary you should just play on Fast graphic settings for leaves anyway.

Why lack of other Client Side Features?

Mods like Mouse Wheelie and Just Enough Items are fantastic. If demand is high enough, I can create a second modpack that includes these additional features, but for the time being this pack's objective is optimisations only.

I'm not seeing a difference in game?

That's sort of the point, this pack tries to keep the vanilla look as much as possible.

I'm not getting much FPS improvements, is the pack broken?

It probably just means you have a good enough computer. If another modpack seems to work better, please drop a comment below and I'll do a comparison.

Another thing you can try to boost your FPS is to ensure your computer is using its Dedicated Graphics Card (if you have one) for Minecraft.

If you have any suggestions for optimisation mods that would fit in this pack, please let me know in the comments.

Optimum (FPS Booster)