Few Item Frames causes lots of lag

I went into a world where there was three item frames on a wall, which caused my 60 fps to go down to 1-3 fps. If the item frame is not rendered, there is no effect. In the item frames, I put some pretty powerful enchanted items (given with command blocks). However, this also happens with an item frame with nothing in it. This didn't happen in 14w03b.