Here http://tomstechnicalblog.blogspot.com/2016/02/rxjava-understanding-observeon-and.html I've found a sentence which I do not understand:
If you have a quad-core, you can optimally support 5 computational threads (4 cores + 1 extra thread for idle time).
What is that 1 extra thread for idle time
for? Is it similar to those "normal" 4 cores
?