upgrades on alienware m17 xr3

[GraphVonKahlen]

Hello

i am looking for upgrading my video card from 560 m to 780 m will it help me to do my 3d modeling and rendering , more in rendering will it reuse render time?
I don't have much money so i am looking for a used video card, same problem 780 m or 780 m sli?

of cours would like to play games to

one of the most inportent question will it work on my alienware pc?
my spec-

Alienware M17 r3

Intel(R) Core(TM) i7-2760QM CPU @ 2.40GHz
12 gb of RAM
video card gtx 560m

thanx you

 

[GraphVonKahlen]

Thanx for answer , it could be good to have one ... but does it work? Yes i can change the video card or for safety i can go to a pc repair shoop next to me to do it for me
wear are you from? i am in france so i would like more info about ... or find something that's increase my render time speed on 3ds max and ather application use. Will it be running on mx 17?