30 fps cap

Hello people of toms hardware, I am having a very strange issue with my PC. When i first start my computer up everything is working fine, i can game at 1080p 60fps and above with no fps cap, but it seems after i open a few apps and tab in and out of games and browser a couple of times ACTIVATE...

My motherboard is ECS H81H3-I/HDMI (V1.0) http://www.ecs.com.tw/ECSWebSite/Product/Product_Detail... my current processor is intel core i3 4130 4th generation http://ark.intel.com/products/77480/Intel-Core-i3-4130-... RAM is hynix 4gb its working fine at 800mhz (1600mhz) but its a single ram...