In those cases, I usually redirect the output to a file, so I can search through it.
Another approach is to run "screen", which has several advantages: (1) not all text needs to be written to the terminal, only the text when you actually look, (2) you can open the computation on a different computer later (e.g. perhaps at home to check if everything is ok), and (3) if you accidentally close the terminal the computation keeps running.
In both cases, my terminal emulator does not need to be fast, really.
My biggest issue with speed in the terminal comes from network latency (which is difficult to fix).