Why is my FPS will reduce after I press the Alt key?

I am experiencing the same issue

This issue also happens with Litematica's 'blockInfoOverlay' feature

For me, it seems to reduce the fps but improve the mspt when the hotkey is held

Accurately, the number of frames will fall sharply when using Tweakroo's InventoryPreview.

This error will return to normal after I disable C2ME.

When pressing F3; in vanilla; with sodium your fps are reduced too.
Most probably not a c2me issue.

Ok, but after disabling C2ME, the problem of fps reduction is solved.

@ilmangoi please provide the following information:

• how many cores and threads you have
• what JVM your using
• if your using client single player, client sever, or server,
• how much memory you've allocated to Minecraft

Please increase the amount of ram to mc and see if you still get perf issues

Preferably upwards of 7gb

1. 4cores,8threads
2. java version "17.0.1" 2021-10-19 LTS
   Java(TM) SE Runtime Environment (build 17.0.1+12-LTS-39)
   Java HotSpot(TM) 64-Bit Server VM (build 17.0.1+12-LTS-39, mixed mode, sharing)
3. single player
4. 4.3GB

Ok, thank you for your reply!

Did that help?

Which is before and which is after

What's the meaning? The FPS is displayed in the upper left corner.

When you did the did the performance go up or down

It is declined, my FPS dropped from 87 to 34

No, there is no improvement

What other mods are you using

What other mods are you using

clientMod\3dSkinLayers-Fabric-1.3.1.jar
clientMod\advancementinfo-1.17.1-fabric0.36.1-1.3.jar
clientMod\AmbientEnvironment-fabric-1.17.1-6.0.22.jar
clientMod\appleskin-fabric-mc1.17.1-2.2.0.jar
clientMod\architectury-2.8.54.jar
clientMod\ArmorSoundTweak-4.0.0-fabric.jar
clientMod\authme-mc1.17.1-2.1.0.jar
clientMod\beenfo-1.17.1-fabric0.36.1-1.3.2.jar
clientMod\betterdroppeditems-1.3.0-1.17.jar
clientMod\betterf3-1.1.5+1.17.jar
clientMod\bettermounthud-1.1.2.jar
clientMod\BetterPingDisplay-Fabric-1.17.1-1.1.1.jar
clientMod\blur-2.4.0.jar
clientMod\bsvsb-2.0.4.jar
clientMod\c2me-fabric-mc1.17.1-0.2.0+alpha.5.0-all.jar
clientMod\carpet-autocraftingtable-1.17.1-1.4.43.jar
clientMod\carpet-extra-1.17.1-1.4.56.jar
clientMod\carpet-tis-addition-mc1.17.1-v1.27.3.jar
clientMod\chat_heads-0.6.0-fabric-1.17.1.jar
clientMod\chesttracker-1.17.1-1.1.1.jar
clientMod\cloth-api-2.0.54.jar
clientMod\cloth-config-5.2.47-fabric.jar
clientMod\Clumps-fabric-1.17.1-7.0.10.jar
clientMod\colorfulsubtitles-1.0.0.jar
clientMod\continuity-1.0.3+1.17.jar
clientMod\Controlling-fabric-1.17.1-8.0.11.jar
clientMod\cullleaves-2.3.2.jar
clientMod\custom-crosshair-mod-v1.3.6-fabric-mc1.17.1.jar
clientMod\deathlog-0.2.2.jar
clientMod\DripSounds-1.17-0.3.0.jar
clientMod\dynamic-fps-2.0.6.jar
clientMod\dynamic-music-1.3.1.jar
clientMod\EnchantmentDescriptions-fabric-1.17.1-4.0.3.jar
clientMod\enhancedblockentities-0.5+1.17.jar
clientMod\entity-outliner-1.2.0.jar
clientMod\EntityCulling-Fabric-1.3.3.jar
clientMod\Fabric-1.17.1-SmoothSwapping-0.4.3.jar
clientMod\fabric-api-0.44.0+1.17.jar
clientMod\fabric-carpet-1.17.1-1.4.56+v211130.jar
clientMod\fabrilous-updater-2.4.jar
clientMod\fallingleaves-1.7.4+1.17.1.jar
clientMod\farsight.fabric-1.17.1-1.5.jar
clientMod\ferritecore-3.1.0-fabric.jar
clientMod\firstperson-fabric-2.1.0-mc1.17.1.jar
clientMod\horse-stats-vanilla-4.1.8.jar
clientMod\hydrogen-fabric-mc1.17.1-0.3.jar
clientMod\illuminations-1.10.1.jar
clientMod\imblockerfabric-1.0.16.jar
clientMod\indium-1.0.1+mc1.17.1.jar
clientMod\InGameAccountSwitcher-Fabric-1.17.1-7.1.3.jar
clientMod\InventoryHUD-fabric-[1.17.x]-3.4.1.jar
clientMod\InventoryProfilesNext-fabric-1.17-1.2.1.jar
clientMod\iris-mc1.17-1.1.3.jar
clientMod\item-model-fix-1.0.3+1.17.jar
clientMod\itemscroller-fabric-1.17.1-0.15.0-dev.20211201.010054.jar
clientMod\krypton-0.1.4.jar
clientMod\lambdabettergrass-1.2.1+1.17.jar
clientMod\lambdynamiclights-2.1.0+1.17.jar
clientMod\lazydfu-0.1.2.jar
clientMod\litematica-fabric-1.17.1-0.0.0-dev.20211203.010230.jar
clientMod\lithium-fabric-mc1.17.1-0.7.5.jar
clientMod\littletweaks-1.0.0.jar
clientMod\malilib-fabric-1.17.1-0.10.0-dev.26.jar
clientMod\MasaGadget-fabric-1.17.1-2.0.7-beta.5085cfc.jar
clientMod\MinecraftCapes+Fabric+1.17.1-11.0.1.jar
clientMod\minihud-fabric-1.17.1-0.19.0-dev.20211027.183903.jar
clientMod\modmenu-2.0.14.jar
clientMod\morechathistory-1.17.1-1.1.0.jar
clientMod\music-duration-reducer-1.2.1.jar
clientMod\namepain-1.4.0+fabric-1.17.x.jar
clientMod\Nimble-1.17.1-fabric-1.0.0.jar
clientMod\notenoughanimations-fabric-1.4.0-mc1.17.1.jar
clientMod\oh-my-minecraft-client-1.17.1-0.3.9.jar
clientMod\paperdoll-fabric-1.0.0-mc1.17.1.jar
clientMod\particleX-1.0.0.jar
clientMod\PerspectiveModRedux-1.17-0.0.5_01.jar
clientMod\plusls-carpet-addition-1.17.1-0.2.2.jar
clientMod\PresenceFootsteps-r35-1.17.jar
clientMod\reasonable-sorting-1.3-mc1.17.jar
clientMod\recipecache-0.2.1-1.17.1.jar
clientMod\RoughlyEnoughItems-6.3.355.jar
clientMod\sharpness-particles-1.0.0.jar
clientMod\slight-gui-modifications-2.0.2.jar
clientMod\smoothboot-fabric-1.16.5-1.6.0.jar
clientMod\SmoothScrollingEverywhere-3.0.3-unstable.jar
clientMod\sodium-extra-mc1.17.1-0.3.6.jar
clientMod\sodium-fabric-mc1.17.1-0.3.3+build.8.jar
clientMod\soundphysics-fabric-1.17.1-1.0.3.jar
clientMod\starlight-1.0.0+fabric.73f6d37.jar
clientMod\syncmatica-0.2.6.jar
clientMod\torohealth-1.17.1-fabric-12.jar
clientMod\tweakermore-mc1.17.1-1.6.1.jar
clientMod\tweakeroo-fabric-1.17.1-0.10.0-dev.20211222.001503.jar
clientMod\TweakMyClient-fabric-mc1.17-1.1.11+925a5bd.jar
clientMod\voicechat-fabric-1.17.1-2.1.28.jar
clientMod\WaveyCapes-fabric-1.0.4-mc1.17.1.jar
clientMod\whereisit-1.17.1-1.14.3.jar
clientMod\xaero-map-addition-1.17.1-0.1.0-alpha 0183cad.jar
clientMod\XaerosWorldMap_1.18.8_Fabric_1.17.1.jar
clientMod\Xaeros_Minimap_21.22.6_Fabric_1.17.1.jar

Try just c2me, starlight, sodium, and lithium and see if you get the same issues

It depends. You shouldnt be using over half ur threads, and make sure your chunk builder is limited with thread count

The only thing that lags is chunk building which is not c2me’s fault

Does c2me reduce in-game fps or not, if not, I will add it to my modpack to speed up chunk loading, if it does, I won't.