yeah i plan to upgrade GPU in future but i will have this gpu some time. i was interested if i would have some serious problems about fps drops , lags and bottleneckWell you probably could get better performance from a GPU upgrade for sure.
yeah i currently have i3-2100 and gtx760 , some heavy bottlenecking are going rnYou probably will just have to turn down graphics settings in some games to get a high framerate, but there really shouldn't be any issues.
You have far more problems with a weak CPU and a powerful GPU than the reverse.
yeah i am aware about motherboardYour aware you need a different motherboard for this CPU correct?
The best CPU you can upgrade to would be an I7 3770k, but a much better value being an I7 2600.