I find that the SSD pays off all over and RAM may not be the real bottleneck.
I have a HP Pro Desk 400 GT Mini with a 2.5 GHz Intel Core I3-6500T processor with 4GB RAM running Windows 7 Professional SP1. It has a convention 500GB hard drive. Periodically I find the computer runs slowly with the small circle going around as it processes commands. I was considering increasing the RAM to 8GB (there is space) but have been told by a couple of sources that switching to a SSD would be a better option. I could do both, of course, but would like some comments from you experts.