Hello, I have a dell xps 8300that I bought from bestbuy. I would like to install another graphics card into it. When I check in control panel what graphics card I have it says I have a Amd Radeon HD 6700 series. When I look it up online it says that that covers multiple graphics cards? So what graphics card do I actually have? Sorry I'm kind of a noob at this. Also my PSU is 340 watts. Thanks!