How to use grep efficiently?

Question

I have a large number of small files to be searched. I have been looking for a good de-facto multi-threaded version of grep but could not find anything. How can I improve my usage of grep? As of now I am doing this:

grep -R "string" >> Strings 

Answer 1

If you have xargs installed on a multi-core processor, you can benefit from the following just in case someone is interested.

Environment:

Processor: Dual Quad-core 2.4GHz Memory: 32 GB Number of files: 584450 Total Size: ~ 35 GB 

Tests:

1. Find the necessary files, pipe them to xargs and tell it to execute 8 instances.

time find ./ -name "*.ext" -print0 | xargs -0 -n1 -P8 grep -H "string" >> Strings_find8  real    3m24.358s user    1m27.654s sys     9m40.316s 

2. Find the necessary files, pipe them to xargs and tell it to execute 4 instances.

time find ./ -name "*.ext" -print0 | xargs -0 -n1 -P4 grep -H "string" >> Strings  real    16m3.051s user    0m56.012s sys     8m42.540s 

3. Suggested by @Stephen: Find the necessary files and use + instead of xargs

time find ./ -name "*.ext" -exec grep -H "string" {} \+ >> Strings  real    53m45.438s user    0m5.829s sys     0m40.778s 

4. Regular recursive grep.

grep -R "string" >> Strings  real    235m12.823s user    38m57.763s sys     38m8.301s 

For my purposes, the first command worked just fine.