I've decided that I'm going to get a Radeon R7 265 gpu and I wanted to know how well it will work with my cpu, a10 5800k, I know its not the most beast cpu out there but it works for me. Also the please let me know if it can I can cross fire it with a second r7 265? would I need something more than a 500 watt power supply? cause I'd love to do cross fire it. What kind of performance increase should expect from that?