mojira.dev
MC-295828

Lag on ARM64 CPUs on newer 1.21.5 snapshots and release candidates

This bug starts on Snapshot 25w09a and is still present on 1.21.5 rc 2. Usually in game, I get around 110-120 FPS on my Microsoft Surface Pro (Snapdragon X Plus model).

In this snapshot and onwards, I get around 40-50 fps.

I am running the game at the same resolution and the same settings on both versions.

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Comments 17

Woo (Bill)

Were there any specific terrain features that could impact performance?

amthyst_

No. I tested the same seed on both versions when I realized the performance felt off.

amthyst_

It’s not because of the new falling leaves either because I tried one of the pre 25w09a versions that had falling leaves and it ran fine. It’s specifically 25w09a and above.

progenitor_amborella

Just tested this using the same world on an M4 processor between 25w08a and 25w09b. The fps while flown up at 32 chunks had actually improved for me on 09b, though sometimes it seems to be near error. I also did not encounter any lag spikes, including whilst flying around.

  1. Enough swing to be in error, but generally positive.

[media][media]
  1. A noticeable improvement. The camera/height adjustment did not affect the fps here.

[media][media]

amthyst_

So I guess that means that 1. Minecraft made some change to the rendering engine between the snapshots and 2. This may be a Windows on ARM exclusive issue.

7 more comments
Sandbox1091

I’m not having lag

Itz_Enter

Yes sandbox this does not affect x86-64 only ARM

Ceresjanin123

I think this and MC-295893 are indeed separate issues as ARM64 devices clearly note a much more severe performance regression than x86 machines.

Kazyn

Have the same issue with newest version 1.21.5, after the update on my Realms world I have very low FPS in some places (even below 30). I play on my Macbook Pro M1 2020. It used to be over 100 fps all the time.

amthyst_

This was mysteriously fixed on my device in a later snapshot of 1.21.6 even though I haven’t seen anything about it in the changelog and this hasn’t been marked as resolved.

I now get fps in the 110-120 range again.

amthyst_

(Unassigned)

Confirmed

Platform

Important

Performance, Rendering

1.21.5 Release Candidate 2, 1.21.5

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