Game Freezes in 1.6

What I expected to happen was...:
Start playing on my server, and join, world begins to render

What actually happened was...:
Joined my server, started to render, then quickly froze, occasionally moving one frame after about two or three seconds. Had to start task manager to exit.

Steps to Reproduce:
1. Start Minecraft
2. Join Server
3. Begin to render surroundings