Transmission

Thanks for the advice. It seems to have helped although I still get choppy cursor movements from time to time. It's just very strange that quitting the program doesn't get rid of the problem.

My MacBook Pro Retina mid-2012 with El Capitan consistently experiences slow-down with 8 simultaneous uploads. The favourites in Finder would disappear, which, admittedly, is a persistent bug in El Capitan, but Transmission would trigger it. The slow-down happens gradually and is generally observed ...