Description

The minecraft client experiences awful fps drops when loading new chunks. This is especially noticeable when spawning for the first time and when loading large amounts of blocks. This doesn't happen on vanilla servers.

Reproduction Steps

1. Start the server
2. Connect from a standard client
3. Cross chunk borders
4. Experience lag

Your Environment

• Operating System: Windows 10

Additional Context

The server doesn't seem to be struggling at all and this bug persists even when the server is configured to only send 1 chunk per tick. To experience this effect to the maximum extent, go to x: -800 z: -1000 on the default seed. Notice the multiple fps drops on the second image.