Anything that fits in RAM on one machine is easily too small for Hadoop. In those cases, the overhead of Hadoop is going to make it get destroyed by a single beefy machine. The only times where this might not be the case is when you're doing a crazy amount of computation relative to the data you have.

Note that you can easily reach 1TB of RAM on (enterprise) commodity hardware now, and SSDs are pretty fast too.

Old but gold post from 2014: https://adamdrake.com/command-line-tools-can-be-235x-faster-...