Question Which ssd to use as boot?

Hello I recently got a BX500 240gb as a gift from a online shop and installed itnin my system. So I want to know that since I already have another ssd in my system which one of the two should Inuse as OS and game drive?
  1. 860 evo 250 as OS and Crucial as Game drive.
  2. Crucial BX500 as OS and 860 evo as game drive.