If you did all of which Evelyn suggested(except for the GPU part since that doesn't affect ping as much as it affects fps), then you're not supposed to be having any problems. Heres a tip: If you have a friend with a faster internet connection than you then try crossfire on his computer,see how it works, check the ping etc. OR boot windows in safe mode with just your network connections and then check your ping. Oh and enlighten me if its only the ping that makes you lag. Tell me your fps.