Minecraft shaders really laggy?

These are my specs:
i3 4160
8gb RAM
R9 270X OC

At normal render distance I'm barely getting 30fps. There are people on youtube with worse graphics cards than I have (like a GTX 750ti) getting like 50fps average with the same settings and shaders.

Andy 15.06.2015

Any modifications? Run the game with Vanilla and make sure your graphics cards settings aren't overriding the AA settings in Minecraft. Minecraft does have performance problems in some cases if settings are overridden by Catalyst or Nvidia Control Panel.

Otherwise make sure your drivers are up to date. I have a card that's not even half of what you have when it comes to performance, and I get around 115 FPS.

You may also want to modify the launch parameters in the Minecraft launcher, launch with more ram, etc. It's Java we're talking about here.

Mike 15.06.2015