Alienware m18x gpu compatability please help

[arkenist202]

I have a alienware m18x R2 and I'm pretty sure the gpu is dead whenever I play games the screen turns I want to get a new gpu but the one it has in it is a bit expensive and kinda hard to find (it is nvidia 675m) I want to get 2 nVidia GeForce GT630M but I don't know if they are even compatible and if they are can you use sli with them or if anyone could offer an alternative that would be similar price

 

[rgd1101]

MERGED QUESTION
Question from arkenist202 : "Alienware m18x gpu compatability please help"

I have a alienware m18x R2 and I'm pretty sure the gpu is dead whenever I play games the screen turns black I want to get a new gpu but the one it has in it is a bit expensive and kinda hard to find (it is nvidia 675m) I want to get 2 nVidia GeForce GT630M but I don't know if they are even compatible and if they are can you use sli with them or if anyone could offer an alternative that would be similar price