If you can spend like 30$ more you can get a decent GPU like the AMD 7770 or a AMD Radeon R7 250X then you can get the optimal performance like 100+ fps. If you are not playing on 1600x900 just play on 1024x768 and many settings on low in that way you can get yourself 150+ stable fps ( I can tell because I also play CS:GO
) and if you are in a tight budget get the Geforce GT 640 but with this GPU I cannot tell what FPS you will get.