The console ones are fastest. They've been around since neckbeards and
sandals were in vogue among programmers. Although some people (RMS) think
they are always in fashion. Most of the basic GUI ones are fast when
compared to a word processor. They tend to be specialised, whereas word
processors are feature rich, which gives them their speed edge. So, it all
depends on what you are trying to do. Look at ones included with small
distributions like Lubuntu and Puppy.