An i5 2500 will get you 200 fps most of the time in CSGO on maps like Dust2, mirage, and cache, but I'd expect it to struggle a little bit to stay above 150 on the newer maps like inferno and Nuke. A 430W seasonic will power that build, but 500W would be more ideal. If you already have the 430W then don't buy a new PSU, not worth it.