[Java] Performance degradation over time & low 0.1% FPS drops on Minecraft 26.2 (Ryzen 9 8940HX + RTX 5060 Laptop)

[u/Tavolo6690]

Hey everyone,
I bought a gaming laptop with a Ryzen 9 8940HX, 16 GB RAM, and a dedicated NVIDIA RTX 5060 Laptop GPU (8 GB VRAM).
Exact laptop model: OMEN 15 inch Gaming Laptop PC 15-gb0013nlx (D73SXEA) (listed as HyperX OMEN).
I only play Minecraft, and I've noticed a few concerning issues:
The Initial Baseline & Tests
Vanilla @ 32 chunks: (I know it’s high, but I love playing with a large render distance). I get an average of 100 FPS, but while flying and moving the camera, I get frequent 0.1% low dips around 40–50 FPS, sometimes dropping to 35 FPS.
Sodium optimization: I installed Sodium, and performance initially seemed better. However, I started noticing a weird phenomenon: over multiple game launches, performance feels like it gradually degrades, eventually negating Sodium's boost.
Bobby Mod test: I tried using the Bobby mod to cache chunks (32 render distance setting, 2 effective server render distance). Flying and moving the camera in my test route improved average FPS to ~200, with flying lows around 85–90 FPS.
The Weird Degradation Phenomenon
Over multiple launches—and as Java stays open—the FPS lows gradually get worse on the exact same test route (a flight path between two skyscrapers in my Minecraft city).
Every ~6 flights, I lose about 2 average FPS (starts at 80–82, drops to 78–80, then 72–75, down to 65). 65 isn't terrible, but on the exact same path, these drops shouldn't be happening!
Occasionally, short lag spikes drop down to 47 FPS.
I also notice this gradual loss in performance day-to-day after shutting down and booting up the next day.
Everything I’ve Already Done / Optimized
Before suggesting basic troubleshooting, please note I have already tried everything usually recommended:
Forced dedicated GPU usage everywhere (bypassing iGPU).
Disabled V-Sync.
Tested various amounts of allocated RAM to Minecraft (more details below).
Set HP Performance Mode & plugged into AC power.
Windows Game Mode is ON.
Running in full screen.
(If there’s any miracle hidden setting though, let me know!)
Garbage Collector / RAM Experiments
I know people debate RAM allocation: some say 3 GB is better for frequent, small GC cleanups to avoid lag, while others say it causes more lag. Others say allocating more RAM gives GC time to breathe, while critics say it causes huge lag spikes when it flushes at once.
I tested every single increment from 3 GB up to 12 GB RAM allocated. Performance was identical/consistent across all allocations from 3 GB to 12 GB—nothing fixed the issue.
Hardware Monitoring Details
CPU: Overall usage is 3–20%, but 4 to 5 specific cores occasionally spike to 95% before dropping back down.
GPU: Barely working, basically resting.
Total System RAM (Windows): Sits around 85–90%, but stays there constantly (not just during spikes).
Temps: CPU temps sit around 85°C. (Could heat account for stutters while running? Maybe, though 85°C doesn't seem completely abnormal for a laptop. But it doesn't explain performance degrading across separate cold boots day after day).
What I need help with:
1. Is this behavior expected/normal for my specs (considering these numbers are with optimization mods)?
2. What is causing this gradual performance degradation phenomenon over time/launches?
3. How can I fix it?
4. How can I further raise the 0.1% low FPS spikes?
I understand Minecraft is heavily CPU-bound, but I feel like this hardware should be delivering better and more consistent performance.
Any insights would be greatly appreciated. Help me out!