hair simulation too slow and cache inaccessible I'm using Blender hair particles for simulating grass and there are two issues.

1) Hair simulation is too slow, even when I set the number to 5 just to check how the grass blades move around. (No there are no Force Fields currently).

2) "Cache" is missing when "Hair" mode is used. This is Blender 2.76b



This means I can neither clear the cache nor bake the animation so I can preview it in the 3d view before so I know everything is fine before running the day-long rendering of the scene.
You should enable Hair Dynamics in order Particle System set to Hair mode to have cache, because


  When set to hair mode, particle system creates only static particles, which may be used for hair, fur...


wiki page.

This type of Particle System may be animated using the cloth solver.

Baking particle system may be neccessary if something happens in the scene, i.e. animation is involved. If dynamic hair is disabled, it seems like hair won't change, so nothing to bake. 

After you enable Hair Dynamics, Particle System will be accessible for baking results and previewing animation when it's played (and so on):