The problem
There are big performance issues with versions 1.13 and above of Minecraft.
A lot of lag spikes appear when the game loads and unloads chunks.
Also, when you open the pause menu of the game, a huge lag spike occurs.
Here are some videos of the problem...
A – When loading new chunks
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B – When loading already generated chunks
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C – When you open the pause menu
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How to reproduce
1. Create or load a world in 1.13 or above
2. Once in play, press Alt + F3 to display the lagometer graph
3. Explore your world and keep an eye on the graph
Also, you can compare the results you get in 1.13 with those you get in 1.12.2. You will see the big difference !
Related issues
Attachments
Comments

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Duplicate of MC-132135.