My computer is five years old but still powerful, not a store-bought machine but custom made. With 8G total memory, 4G assigned to Minecraft through the launcher, and a 2G AMD video card, I run 150- 300 FPS with a 512X texture pack (forge and optifine running.) But when I apply a shader (and I've tried a lot of them), 90% of my FPS vanishes.
Shaders don't just slow me down, they cripple me. I tried dropping my texture packs down to 256X, 128X, even 64X, no matter, my game is still crippled. Even at 32X or vanilla graphics I struggle as if with a cheap computer.
Am I missing something or is this normal?
And speaking of shaders, omg, what a pain to get one to "activate." When I try to load a shader the game stalls with "not responding" to the point where it can take up to ten minutes to get the shader to kick in. I get this a little bit now and then with texture packs but with shaders it's a nightmare. Same with trying to change any setting within a shader.