I get 300 FPS with 80% GPU usage on 1.21.4 using complementary unbound shaders, and on 1.21.5 with the same settings i get 100 FPS less and 100% GPU usage. These performance regressions on the vanilla client could be due to many things and should immediately be looked into by Mojang.
MC-297092
Incredibly regressed performance with shaders and without shaders using Iris on 1.21.5 compared to 1.21.4 and future snapshots
Resolved
Invalid
1
Thank you for your report!
However, this issue is Invalid
Simply stating that "My game is laggy" is not helpful for Mojang to diagnose your issue. If you can pinpoint a specific cause when lag happens for you, please open a new report for that specific issue. If you think this might be a hardware issue please contact Community Support as they might be able to help with your issue.
Keep in mind that Mojang is constantly optimizing the game and simply playing the game provides feedback to Mojang on which parts cause performance issues. To learn more about this, head here (section "Telemetry") for more information.
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