It's the game and is a known (to us) issue. Bioware has yet to respond.

Agreed with the OP here. I run this game well above minimum specs and I do perfectly fine with all settings on high in windowed mode while questing solo or with multiple people including flashpoints. But when I join a warzone everything goes to hell. Even with all settings on low in full screen mode I don't even come close to being able to enjoy myself. Considering I purchased this game intending to focus on PvP I honestly don't know how long I can convince myself to keep paying for it. It's really unfortunate because I'm loving my class quest, but that can only keep me interested for so long.

Warzones are totally unplayable for me. I'm running the game far far above minimum specs on low graphics in full screen mode with no background processes running. I really really hope they fix this or I don't know what I'm going to do.