Extreme low performance on high end pc

First of all let me describe my specs:

• CPU: Intel Core i9 12900K (16 cores, 24 logic processors, 3.2Ghz base, 5.2Ghz boost)
• RAM: DDR4 80Gb 3200Mhz
• GPU: Nvidia RTX 3080 TI (12Gb Gddr6)
• SSD: Kingston NVME 2Tb (write/read 7000MB/s)

Now, I'm playing Minecraft 1.20.1 with Forge + Optifine, currently I'm using BSL shaders (although I was previously using SEUSS PTGI), also I'm using a texture pack (Faithful 32 or 64), when not using this mod, I run at 60+ fps stable, but as soon as I enable this mod it starts working at 50- fps... so much for the "not affecting performance"...

Please, either fix this or help me set the mod up properly. I don't think I should be having this kind of fps drops with my current setup.

Thanks.-