Intel Atom CPU has not been designed with games in mind.
You will need a different Motherboard & CPU (i3 or i5 cpu)
What you might be doing (but will not help too much) is while you play the game, close all programs in the background (IM messenger, skype, antivirus, backup jobs etc)
Once you exit the game, enable back the antivirus and all the other programs.
Hope it helps.