I don't have the exact numbers on hand but, when the 3D team recomputed it for rerelease I'm told it took mere days to render what took us months in 1995. Computers are way faster now, and we have more of them.
Our render times per frame have stayed pretty much flat for the last 30 years. When machines get faster we just ask them to do more. I call it the Law of Constancy of Pain.
Update:
[I finally got approval to post this answer. It's really provided by one of our rendering gurus. I just edited it a bit. -- Craig] Toy Story was originally rendered back in 1995, and to our best estimate probably had frame render times which averaged in the range of 4 hours or so. When we went to rerender it, we obviously didn't want to be forced to use the same kinds of machines that we used back in 1995, so we made an effort to port the software that we used forward to more modern machines. In testing, we discovered that some minor incompatibilities that had crept into RenderMan since 1995 made it better to target an intermediate version of RenderMan, notably, version 12.5. Similarly, menv had gone from its original architecture to one based entirely upon hooks. ("Hooks" were a way of including models and such in a shot via reference, and replaced a C-like #include/function call paradigm.) We reverted to the last version of menv that was still capable of loading the original models, which was version 22. The rendering provided an interesting test of Moore's Law. Well, not the real Moore's law, but the one that says that computing power doubles every 18 months. In 15 years, we'd get 10 doublings, which would make modern computers 1000x faster. Our original Toy Story frames were averaging four hours, which is 240 minutes, so we might naively expect that we could render frames in just 15 seconds. We didn't really achieve that: our average render times were probably on the order of 2-4 minutes per frame (the original productions weren't instrumented to keep accurate statistics on rendertime, and we never bothered to really reinstrument them to do so.) The renders were fast enough that most of Toy Story was rerendered in "render farm white space", we never had any sizeable backlog of work queued on the farm. TS2 was substantially more complex: we averaged rendertimes of maybe 20-30 minutes per frame, with some especially difficult scenes taking maybe 40 minutes.
