Low fps at gta 5 start

[xephobia]

Hey so i usually get around 60fps last time on the same system at high mixed with very high and now i only get like 40-50 fps and everytime i startup gta5 i always get 20fps and now its getting a bit hard to navigate the menu can anyone help me ?
my specs :
i3-4170
gtx960 windforce 4gb
8gb ddr3 hyperX fury ram
120gb ssd
1tb hdd

 

[vrumor]

Where did you download GTA V from?

 

[xephobia]

Where did you download GTA V from?

downloaded from steam

 

[vrumor]

Try verifying the files?

 

[xephobia]

Try verifying the files?

still nothing :V