I use an old SSD, to hold my system temp folder, windows updates and swapfile, SSD's don't like lots of small writes, so if the old SSD does die after a few years of use, don't really care and still faster than a HDD.
I get why people would want to install 500GB to 2TB SSDs but what would smaller drives be used for? 128GB, 256GB etc. Just curious...Thanks
If you're careful and diligent, a 120GB will work for "only windows''.
That takes some maintenance, though.
My wifes system is a single 250GB SSD. No problem.
Facebook and email...nothing large installed.
My main system, all SSD:
From top to bottom:
500GB - OS and applications
250GB - CAD/video work
250GB - cache space for applications and pagefile
960GB - games, and everything that does not fit elsewhere
120GB - Old OS drive (2012), just in there for testing
500GB - photo work
The 500GB photo drive is soon to be replaced by a 1TB (in the mail from Newegg)
NOTE: All these drives did not happen at once. They were gathered over the years.