Hello,please help me.My games are very laggy after upgrading pc.my specs are:10GB Ram,2GB ASUS GEFORCE 710 2GB SL,AMD PHENOM 2 X4 955,HITACHI 500GB HARD DISK,AND POWER SUPPLY 550W.Before the upgrade games were running completely fine,I only upgraded from AMD RADEON HD6800 Series to asus nvidia gt710 sl 2gb,and games which were 60-30 fps are now barely around 20fps(games like skyrim,dota 2,gta iv...).What could be the problem?