I always use a second SSD for my game installs (although technically I have three other SSDs with games on, because I hate re-downloading them), and I think everyone should. It's not about performance ...

Grand Theft Auto V Rise of the Tomb Raider - 01:23 The Witcher 3 - 02:49 Mass Effect Andromeda - 04:05 Fallout 4 - 05:41 ...