safe and efficient settings for what? if you mean for the 1050ti then try around 100mhz for the core clock and 150-200mhz on the memory clock. try opening a few games and if the game crashes after 10 minutes or so, drop the speeds down a bit and keep trying in-game until everything is stable. if it is stable at first keep adding speed until it begins to crash, then revert back to the last stable configuration.