Quote: "30 fps would not bother me if my text and reticle were not flickering."
Flicker is an entirely different issue than frame rate, I'm afraid. The human eye acknowledges something around 24+ images per second as "real-time."
So if the reticle is flickering, it's probably because of the way you have coded the reticle.
It's also important to first turn sync on and THEN set the sync rate. And furthermore, it doesn't matter how tough your computer is if you strain it too much. So what are you actually doing in your program?