hello, so i got atleast i guess "glitched" gtx560ti its over heating on better games reaching like 100 degrees even when fans spinning on 100%, once i tried radeon 6x from my brother pc some games were laggy but atleast i was able to play them. With my gtx560 i can play league of legends without getting overheat. Since my brother playing only league i would like to switch those cards but im afraid to since i know that can something bad happen with too less psu power or what ever. I got like 500w one and his only 400 as i remember. Is it even posible to change those cards and what should i know before doing it?