ATi Graphics card help

hi how are plz help me can
crossfire ati 2900xt 1gb with ati 2900xt 512mb

Hello, Beka & welcome to the forum.

Please explain more thoroughly & clearly what you need.
Are you trying to “tie” the two graphics cards together using ATI’s crossfire platform ?

yes you can crossfire a 1gb 2900xt with a 512mb 2900xt, but it will behave like 2 2900xt 512 in crossfire