So I used to use cracked Minecraft (TLauncher and yes I know i was a poor 15 yr old who couldn't afford it so I was like "hey lets pirate" it was dumb its in the past don't flame me). When I would start the game it would start pretty quick (like 30 sec to 1 min) and I would get a stable 120-180 frames but ever since I decided to stop being an idiot and bought Minecraft it takes like 5-10 MINUTES to start and I get 120 or so frames but not stable it will constantly drop down to 20 or 30. I have tried using Badlion Client and OptiFine to no avail. I have the same amount of RAM allocated as before (2048M) and am using the exact same texture packs (Faithfulx32, The F++ Addon, Visual Enchantments, Redstone Utility Pack). I have a low end pc so when playing Minecraft I usually only have Microsoft Edge (I know eww but it takes less ram then Google or FireFox) with discord open. Does anyone know why all of the sudden my game is doing so much worse?
Edit: Btw my PC has 3.9G usable RAM on the system (4G total)
I monitored the CPU at startup and noticed exactly what you said where at startup the CPU would jump to exactly 50% usage (which is expected since Minecraft doesn't make use of more then 1 core) then as soon as the game started it dropped to 30% HOWEVER It has always done this and I'm curious as to why all of the sudden this would become a bottleneck. I have tried closing all other programs and disabling all texture packs to no avail. Here's the weirdest part I ONLY see this behavior when launching from the Minecraft Launcher (I said this happened with badlion too but it seems to have fixed itself). And the even weirder part, when using the CurseForge Launcher It launches just fine. This problem is SPECFIFCLY with the Minecraft Launcher Installed at Program Files (x86). I thought maybe it could be a fragmentation error where the Launcher was having a hard time reading my game directory so I defragmented my hard drive and cleaned out all of my useless junk and still nothing. Now here's what happens. I have a bad pc so when Minecraft first starts it will show Not Responding this happens regardless of where you launch however where it changes is at load. On Curse and BadLion it will load almost instantly 10-15 seconds however on the Minecraft Launcher it will load to like 80% then freeze and just sit there for 5-10 minutes. I have not altered any settings that should effect this. It's a really weird error and also to add to the weirdness this error is SPECIFICLY 1.16.4. 1.8.9; 1.16.3; and Snapshots launch just fine. I thought maybe it could be my install of 1.16.4 so I went into my .minecraft folder and deleted all libraries and the version folder for 1.16.4 and tried a fresh install and STILL NOTHING. I am at a complete loss for why this would be happening. I'm pretty tech savvy and I'm even a backend java developer FOR MINECRAFT so I have a good understanding of how java and Minecraft work and even I have no clue wth is going on. If you have any idea why please let me know but if not I can just use badlion for 1.16.4 for the foreseeable future.
Thank You for trying to help
TL;DR: Problem is isolated to Minecraft Launcher AND specific version 1.16.4, CPU has never been bottleneck in past.
I unfortunately only have one physical hard drive (2 partitions) I think for the time being he best bet is just to use badlion. And also you will learn and honestly your right around the age when I started getting into java development (I’m 16 now) if you wanted to do that I would recommend starting with spigot plugins then eventually graduating to mods but anyways thanks for trying to help have a nice night.
3.9 GB of free RAM is the bare minimum to use post 1.13 minecraft with default settings, even under less resource-hungry operating systems like linux, I'm not surprised it gets awhile to launch, with the textures and everything else on the low-end cpu.
If you have problems just with the launcher, you can try to launch minecraft with MultiMC (you have to insert your mojang account, so you aren't pirating anything, Minecraft it's still the original, only the launcher changes).