I'd start here: https://github.com/Rdatatable/data.table/wiki/Benchmarks-:-Grouping https://github.com/Rdatatable/data.table/wiki/Benchmarks-:-G... Performance

I'd start here: https://github.com/Rdatatable/data.table/wiki/Benchmarks-:-Grouping https://github.com/Rdatatable/data.table/wiki/Benchmarks-:-G... Performance isn't currently a huge focus for dplyr. In my opinion dplyr is fast enough that the bottleneck becomes mostly cognitive - you spend more time thinking about what you want to do than actually doing it.