The only time I had severe latency issues... I called my ISP... i'm not very tech savy... they informed me I had incredible speed coming through my lines but my modem, router, and cables were ancient in comparison... basically choking it up.. if someone in the house used netflix or roku... i could not play wow what so ever due to 300-3000 ping depending on the night
went and bought a few cat5e cables (over a year ago when they were new tech) along with new modem and router... now i can run lag free in almost any game, movie downloads went from an hour to under 3 minutes.. i dunno just check to make sure your hardware isn't crap