DesertLobster

Also happened to me on a dedicated server with 1.21.1. I couldn't see my friend that was standing right in front of me. I disconnected and reconnected which fixed it.

Also this was while using a dedicated server, not LAN

Still an issue in 1.21.1. Haven't tried with 1.21.2 yet. Only noticed it with 3 players. Not sure if that's just a coincidence or not, but never noticed it with only 2 players. Disconnecting and reconnecting seems to fix it.

Well actually looks like MP does have less explored. Although I'm pretty sure it was immediately worse than when I was playing MP (played MP first). Soo I still doubt that's the issue. MP: SP:

About the same in both. Slightly more spread out in SP world with maybe slightly more ground storage but not enough of a difference that should matter. MP: SP:

Barely built in either world. One house built in both of them and more so dug into the environment. About the same progress in both. In fact I think the multiplayer one has more discovered in it.

I turned VSync off already. Also disabled optimizing RAM as suggested by the wiki to allow it to use all the RAM that it wants to since that shouldn't be a problem for my setup.

Wanted to add some proof. Here's it performing great in multiplayer: First loading into singleplayer: : And then drops down to 45 FPS and hovers between there and 60 FPS for the most part: Graphics settings are all the same between both. And the multiplayer server is hosted on the same PC I'm playing on.

I'm truly confused by how the performance is so much worse in singleplayer versus hosting a dedicated server and playing the game on the same PC. When running a dedicated server and playing multiplayer I'm getting 100-144 FPS with graphics maxed even when playing with a friend. When I play in singleplayer I'm getting like 50-80 FPS (same graphics settings). So basically runs at half the performance when playing singleplayer. Even if singleplayer is hosting a server and I'm playing it, it should have better performance than multiplayer since I'm doing the same thing but my friend is also playing on the server at the same time. Why is it so much worse? Is there something I can do to fix this or is it a known issue? I don't just want to play solo on the server since I'd prefer to just play that world with my friend. My PC is for reference: Ryzen 9 7900x, Radeon 7800xt (16 GB VRAM), 64 GB RAM, OS: Windows 11