Speeding up Grep on Large Files

Here are a few tips to improve the performance of grep on large files:

1. Prefix your command with LC_ALL=C, in order to use the C locale with its smaller ASCII charset, instead of UTF-8
2. Use grep -F to search for a fixed string (if possible), rather than a regex
3. Remove the -i option, if you don't need it

LC_ALL=C grep -F searchString largeFile