This question is inspired by this article.
Currently I spend a lot of time in R to analyze data. Some of the scripts I run in R could benefit from parallel computing in order to save time. Let's say I could build a barebones "real" computer for maybe ~$300 and for that same $300 I could get 6 Pis (including power cable and SD card). Assuming I had a task that was well suited for parallelization would I be better with the Pis or the "real" computer?
Would the answer change if I ramp up the "real" computer's hardware to something that may cost $1000 how would that fare against 20 Pis?