A pack put together to give you maximum performance out of your hardware while playing vanilla Minecraft.
Performance increase as much as up to 10 times with mods optimizing almost every aspect of the game while leaving the vanilla mechanics intact.

List of mods included :

1. Alternate Current : An efficient and non-locational redstone dust implementation.

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2. C2ME : A Fabric mod designed to improve the chunk performance of Minecraft.

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3. Clumps : Clumps groups XP orbs together into a single entity to reduce lag when there are many in a small area. Ontop of this, it also makes the player immediately collect the orbs once they touch the player, so you are not stuck with a bunch of orbs in your face.

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4. Enhanced Block Entities : EBE Makes chests (and soon to be more block entities) use baked block models rather than laggy entity models.

WITHOUT EBE :

WITH EBE:

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5. FerriteCore : This mod reduces the memory usage of Minecraft in a few different ways.

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6. Iris : A new shaders mod for Minecraft intended to be compatible with existing ShadersMod/Optifine shaders.

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7. Krypton : Krypton (from Ancient Greek kryptos, "the hidden one") is a Fabric mod that attempts to optimize the Minecraft networking stack. It derives from work done in the Velocity and Tuinity projects.

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8. LazyDFU : LazyDFU is an optimization mod that makes the initialization of DataFixerUpper "lazy" - that is, it will not immediately create the rules required to migrate data from older versions of Minecraft to newer versions until it actually needs to do so.

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9. Lithium : Lithium is a general-purpose optimization mod for Minecraft which works to improve a number of systems (game physics, mob AI, block ticking, etc) without changing any behavior.

via Lithium's Curseforge page
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10. Observable : Observable profiles (tile) entities and shows you what's taking up tick time and where.

via Observable's Curseforge page.
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11. Recipe Cache : Caches recipe lookup for crafting and furnaces to lessen server lag caused by crafting stacks of items and large amounts of furnaces ticking.

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12. Smoke Suppression : This mod prevents campfires from creating any particles when certain blocks are underneath them. It affects both standard and soul campfires.

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13. Sodium : Sodium is a free and open-source rendering engine replacement for the Minecraft client that greatly improves frame rates, reduces micro-stutter, and fixes graphical issues in Minecraft.

via Sodium's Curseforge page.
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14. Starlight : Fabric mod for completely rewriting the vanilla light engine.

via Starlight's github page.

(A lot of these mods are incompatible with Optifine and are meant to be a better replacement for it with magnitudes of better performance increase)

MC Ultralight