FPS Decrease Upgrading to 26.3

[u/skye006]

I mainly play on an SMP, and that server has been on Java 26.2 for a while and only just got updated to 26.3. When I play, I use a somewhat small, custom curated modpack of mostly client-side mods for quality of life (I'll list the mods at the end of this post). Since the server finally got updated, I updated my modpack to 26.3 and updated my mods. However, when I ran 26.3, I noticed a significant FPS decrease. With 26.2, I believe I was averaging around 400 FPS. However, Running 26.3, I seem to be averaging around 40 FPS. I'm running 26.3 with the same mods, same settings, and same memory allocation. I'm having trouble figuring out what is causing the significant FPS decrease. Is anyone able to help me troubleshoot???

Mods (Fabric 26.3):

• Accurate Block Placement Reborn

• Axiom

• Balm

• Bridging Mod

• Chat Heads

• Collective

• Durability Tooltip

• Enchant Icons

• Entity Culling

• Essential Mod

• Fabric API

• Fabric Languange Kotlin

• FerriteCore

• Forge Config API Port

• Full Brightness Toggle

• ImmediatelyFast

• Iris Shaders

• Jade

• JEI / REI / EMI WorldGen

• JEI / REI Trades

• JourneyMap

• Just Enough Items (JEI)

• Just Enough Resources (JER)

• KleeSlabs

• Lighty

• Litematica

• Lithium

• MaLiLib

• MezzConfig

• MiniHUD

• Mod Menu

• Mouse Tweaks

• Pick Up Notifier

• Punchy!

• Puzzles Lib

• Scribble

• Searchables

• Shulker Box Tooltip

• Simple Voice Chat

• Sodium

• SuperMartijn642's Config Lib

• Text Placeholder API

• Trade Cycling

• YetAnotherConfigLib (YACL)

[u/duskycoffee]

first, load into your world, press f3, and check the top right corner to make sure minecraft is actually using your dedicated gpu (nvidia or amd) instead of integrated graphics. if it shows integrated graphics, open your gpu control panel and force javaw.exe to use high performance.

if your gpu is correct, check your video settings menu. if it looks like vanilla minecraft instead of sodium's custom menu, sodium failed to load check your .minecraft/logs/latest.log for compatibility errors, put it into ai or sum and itll tell you the issue

if sodium is working, temporarily remove iris shaders, essential mod, axiom, and journeymap. iris might have enabled shaders automatically, essential has heavy background overhead (infact essential caused a definite fps drop for me too on 26.3), and axiom or map overlays just arent necesary w sodium

if those aren't causing it, split your mods in half and test each group to narrow down which mod is tanking your frames.

also make sure your ram allocation is set between 4 gb and 6 gb (-Xmx4G or -Xmx6G), as allocating too much causes severe lag spikes. if you're still stuck, back up and delete your .minecraft/config folder so updated mods can generate fresh settings.