Lags with this resource pack when using shaders

[Kilaun]

Hello, I have a big problem with FPS and I absolutely do not understand why. I recently bought this laptop: Acer Nitro V15 product, which has RTX 4050 and Intel Core i5-13420H. When I turn on Minecraft (normal version without optifine) it does not crash and i get about 150-180 FPS.But once i install Optifine (latest version 1.20.4) and Rethinking Voxels shaders and also SpHax purebdcraft texture pack and it immediately starts to crash. Or it doesn't completely crash, but I have like 20-30 FPS, which I don't understand. This laptop should be good, right? Could someone please help me? My VSync is off and render distance is on 10.. Thanks a lot

[HanFox]

Shaders are always going to be a big hit for your FPS.

You might want to think about not using OptiFine and try Sodium with Iris instead as Sodium generally works better with modern hardware.