Low FPS with Shaders
hey everyone, having some weird issue with shaders. without i get a solid 350fps with any shader pack (tried 6) im stuck around 30ish fps
tried even minimalist vanilla shaders, set settings to very low - no change
13th Gen Intel(R) Core(TM) i9-13900KF
4090
very low usage in task manager for memory, cpu, gpu
latest nvidia drivers - added javaw to control panel to make sure 4090 is being used
55 Replies
=== System Specs ===
CPU: Intel Core i9-13900KF (24C/32T, ~5.1 GHz boost)
GPU: NVIDIA RTX 4090
Monitor: 3440×1440 ultrawide @ 240 Hz
Java: Azul Zulu 17 (also tested 21)
OS: Windows 11
NeoForge 1.21.1
=== Problem ===
- 300+ FPS without shaders
- ~30 FPS with any shader pack (Complementary Reimagined non-RT, Bliss 2.0.4, Chocapic, Minimalist, etc.)
- GPU usage ~30% when shaders enabled
- CPU usage ~40% overall, never maxed on one core
- Other games run fine
Tried a number of different ram settings from 8-16-24 (curseforge)
no java arguments
=== What I’ve Tried ===
FPS caps / sync:
• In-game max FPS = Unlimited
• V-Sync = Off (Minecraft + NVIDIA Control Panel)
• NVIDIA Max Frame Rate = Off
• Monitor confirmed 240 Hz
• Disabled overlays (Discord, NVIDIA, Xbox Game Bar)
NVIDIA settings:
• Added correct javaw.exe for both Zulu 17 & 21
• Power management = Prefer Maximum Performance
Java runtimes:
• Tested Azul Zulu 21 → bad performance
• Installed Azul Zulu 17 (LTS, supported) → no change
Drivers:
• Clean install of latest NVIDIA drivers
Pastebin
alloy-forgery-2.4.1+1.21.jaramendments-1.21-1.2.24-neoforge.jarappl...
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Send a f3 screenshot
any other data you need?
i tried on my other pc - which has a slightly better cpu and also has a 4090 - and same issue. high fps without shaders - very very low 10-30 with
if anyone could help with a line of troubleshooting id be greatful
For sanity check, how much frame rate you get if you set the game window to 1080p?
still terrible - no real change
There is definitely a problem somewhere in that case.
any idea?
can anyone help?
how quick is your ram
idk if a ram bottleneck would look like this but better safe than sorry
exactly same problem here. Its been there even after a clean windows installation. must be something on the hardware side more than software side
i still dont understand what the issue could be tho, and nobody who tried to help me provided a real solution so for now I play with no shaders at all, copium.
have expensive ddr5 ram - i think around 7000 - 64gbs
no clue whats causing it - bummer
hi
i am finally here
have you tried creating a spark log? (Also, trying Fabric instead of NeoForge)
to create a spark log, download the Spark mod, then run
/sparkc profiler --timeout 20 (not spark!) with shaders on and play for 20 seconds until it gives a linksorry for late reply ill try that now
trouble here would be reproducing the mod loadout
here is results WITHOUT shaders
spark
spark is a performance profiler for Minecraft clients, servers, and proxies.
here is results WITH shaders (bad fps)
https://spark.lucko.me/lvT6RsiTCd
spark
spark is a performance profiler for Minecraft clients, servers, and proxies.
@IMS
w
what the fuck am I looking at
Good news
I found your problem
take a look at your log files and tell me how big they are, please
some horrible tragedy has taken place with your mod combo causing thousands of errors per frame
strange that it only seems apparent with shaders though haha
let me find my log
yes; seems like the bug only happens with shaders
I'm not able to see what message it's trying to send from the spark log alone
you want latest?
or debug
but I can tell it's caused by Kleider's Skin Renderer
debug
idk what that even is lol
huh
i don't see any errors
weird
CurseForge
Kleiders Custom Renderer API
Change the player/mobs models and textures with this API for MCreator mods!
4.2M Downloads | Mods
this... thing
likely a mod you have is including it
yeah
nvm i see it in mods
if I had to guess, it's BackpackPixel and ProtectionPixel
based on the stack frames
let me remove see what mod requires and test without
you are not the first person to report problems with this mod, it seems
and the dev has been silent
i remove backpack pixel, protectionpixel and the api.
you're a troubleshooting god
went from like 20fps with shaders to 235
:aolslow:
you could tell all that from spark? I should try to learn to read that lol
I'd say to report it... but it doesn't seem like reports are being listened to
so you're kinda screwed
i dont care about those mods at all, just were throwin in on a modpack that im using as a starting point
eh, I just went down the graph
shaders well worth it over those lol
and mods generally name their injections
so it wasn't too hard lol
oh cool thats pretty self explanatory
still interested in finding out the cause, but not going to mess with it right now
greatly appreciate your time and assistance.
no problem
Maybe, just maybe, I should also consider Spark as a tool for debugging, despite the difficulty on tracing the tree.
:yes:
there's actually a much better view lol
you can just click mods and it shows you an approximation of what mods are taking time
however, it is very often wrong
im just happy to learn of any tool to help with troubleshooting
(for example, it's blaming Iris for 90% of performance here due to the stack)
no problem
you can use the
spark command instead of sparkc to look at server performanceSure got me before, back when I'm trying to read a Spark log and it putting Distant Horizons at the top.
:yes:
Speaking of Distant Horizons
based on your log, you somehow have a corrupted Distant Horizons save
not sure if you care, but might want to figure that out if you want to use DH
(honestly, I have no clue if that error actually matters...)
Two issues, one spark log to reveal?
:flooshed:
oh! interesting to know thanks - is it the save game i was loading? thats just for testing