One cell in my notebook executes for a long time, while the other CPU's in the machine are idle. Is it possible to run other cells in parallel?
Not magically, and probably not what you think but yes. Here is the documentation for ipyparallel (formerly IPython parallel) that will show you how to spawn multiple IPython kernel. After you are free to distribute the work across cores, and you can prefix cells with %%px0 %%px1... %%px999 (once set up) to execute a cell on a specific engine, which in practice correspond to parallel execution of cell. I woudl suggest having a look as Dask as well.
来源：https://stackoverflow.com/questions/21248345/is-there-a-way-to-run-multiple-cells-simultaneously-in-ipython-notebook