I need to know your level, your crit rate, your itemziation you are planning to go for or already have, and mainly, your weapon and physical attack.
The more crit rate you have, the more DEX becomes more optimal in comparison to STR. The Closer it gets to 100% crit chance, the more STR becomes more optimal than DEX. It is exactly like a triangle. 100% crit chance being the roof. (It is not only this, but i am lazy to type it up).
You also have to tell me if you want to consider any supports or buffs outside of level 5 finestra.