The Ryzen 5 1400 CPU is, so far, the most inexpensive AM4 CPU (this title will be soon taken by Ryzen 3 CPUs, when they were launched). It means it is a mainstream model, focused on cost/benefit ratio. If we think about applications that use multiple threads simultaneously, it actually delivers a good performance for a decent price.
In games, things are a little different. It is fast enough to run all games decently, but it was a little slower than the Core i3-7350K and even to the Core i3-76100, which costs less. So, we can conclude the Ryzen 5 1400 hasn’t a good cost/benefit ratio for gaming.
However, we need to keep in mind its overclocking potential: the Ryzen 5 1400 suffers because of its low clock (3.2 GHz) but it can easily be set to work at 3.9 GHz (or close to this.) So, if you intend overclocking it, this CPU can be an excellent choice, taking benefit from the clock raise.