I'm a little confused on the whole rendering process. They said it takes at least around 24 hours to render 1 frame, and that there are 24 frames in a second. If you take a 100 minute movie, then it would take around 400 years to render that many frames. I understand that they would have many machines, but even with 400 machines it would still take a year just to render. My best guess is they have around that many machines or maybe more, and they render as they go so they don't have to wait a year after finishing the movie to render, but I would appreciate a little more explanation.
Pixar has a huge "render farm," which is basically a supercomputer composed of 2000 machines, and 24,000 cores. This makes it one of the 25 largest supercomputers in the world. That said, with all that computing power, it still took two years to render Monster's University.