I have a lenovo z500 laptop with 8gb of ram and an i5 ivybridge duel core cpu i have a computer i can play most of my games on but for travel the integrated hd 4000 graphics are not really cutting it in games like dayz or cs go i mostly play the mod of dayz not the standalone if that makes a difference in your answering of my question but i would really enjoy it if i could play games at reasonable frame rates on my laptop the lenovo website says that it is only compatible up to a nvidia geforce gt 645m and i cant seem to find a proper website to order one in fact the nvidia website says that they don't sell any mobile gpu's to anyone but manufacturers i was wondering if there would be any website i could order a mobile gpu from and if so what gpu would work because the 645m is already 3 gens old and i am not sure if i could find one if there is an alternative to it in the 700 or 800 series of gpu's i would be glad to know where to get and if it will work with my current laptop i am planning on upgrading it myself but if anyone has any idea of a company that could easily upgrade it and get the parts that would be appreciated as well thank you for your time