FPS drop when wielding enchanted tool/weapon

When holding an enchanted tool/weapon in my hand (any so far), my FPS instantly drops by 50% or more on any settings. Has to do with the animation rendering or something, my memory doesn't spike but it steadily goes up like there's a leak or something.

Pictures shown are on the absolute lowest settings aside from FPS limiter, which is set to unlimited so there's nothing to mess with my FPS. I'd do it on higher settings but there's no point because 13w38a-c snapshots all give me terrible performance regardless of the tool bug.