GNU grep is fast, but there are certain alternatives that are pretty fast (probably faster):
- ack [0]
- ag (also known as the silver searcher) [1]
You could make `grep` faster by telling it to interpret the pattern as a fixed string (-F or --fixed-strings) is you're not using a regex. Setting to LANG to C would also probably make it faster.
[0] http://beyondgrep.com/
[1] https://github.com/ggreer/the_silver_searcher